Graphene-coated sand for enhanced water reuse: Impact on water quality and chemicals of emerging concern.

This paper investigates the potential of graphene-coated sand (GCS) as an advanced filtration medium for improving water quality and mitigating chemicals of emerging concern (CECs) in treated municipal wastewater, aiming to enhance water reuse. The study utilizes three types of sand (Ottawa, masonry, and concrete) coated with graphene to assess the impact of surface morphology, particle shape, and chemical composition on coating and filtration efficiency. Additionally, sand coated with graphene and activated graphene coated sand were both tested to understand the effect of coating and activation on the filtration process. The materials were characterized using digital microscopy, Raman spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction analysis. The material's efficiency in removing turbidity, nutrients, chemical oxygen demand (COD), bacteria, and specific CECs (Aciclovir, Diatrizoic acid, Levodopa, Miconazole, Carbamazepine, Diphenhydramine, Irbesartan, Lidocaine, Losartan, and Sulfamethoxazole) was studied. Our findings indicate that GCS significantly improves water quality parameters, with notable efficiency in removing turbidity, COD (14.1 % and 69.1 % removal), and bacterial contaminants (64.9 % and 99.9 % removal). The study also highlights the material's capacity to remove challenging CECs like Sulfamethoxazole (up to 80 % removal) and Diphenhydramine (up to 90 % removal), showcasing its potential as a sustainable solution for water reuse applications. This research contributes to the field by providing a comprehensive evaluation of GCS in water treatment, suggesting its potential for removing CECs from treated municipal wastewater.

2D Fluorinated Graphene Oxide (FGO)-Polyethyleneimine (PEI) Based 3D Porous Nanoplatform for Effective Removal of Forever Toxic Chemicals, Pharmaceutical Toxins, and Waterborne Pathogens from Environmental Water Samples.

Although water is essential for life, as per the United Nations, around 2 billion people in this world lack access to safely managed drinking water services at home. Herein we report the development of a two-dimensional (2D) fluorinated graphene oxide (FGO) and polyethylenimine (PEI) based three-dimensional (3D) porous nanoplatform for the effective removal of polyfluoroalkyl substances (PFAS), pharmaceutical toxins, and waterborne pathogens from contaminated water. Experimental data show that the FGO-PEI based nanoplatform has an estimated adsorption capacity (qm) of ∼219 mg g-1 for perfluorononanoic acid (PFNA) and can be used for 99% removal of several short- and long-chain PFAS. A comparative PFNA capturing study using different types of nanoplatforms indicates that the qm value is in the order FGO-PEI > FGO > GO-PEI, which indicates that fluorophilic, electrostatic, and hydrophobic interactions play important roles for the removal of PFAS. Reported data show that the FGO-PEI based nanoplatform has a capability for 100% removal of moxifloxacin antibiotics with an estimated qm of ∼299 mg g-1. Furthermore, because the pore size of the nanoplatform is much smaller than the size of pathogens, it has a capability for 100% removal of Salmonella and Escherichia coli from water. Moreover, reported data show around 96% removal of PFAS, pharmaceutical toxins, and pathogens simultaneously from spiked river, lake, and tap water samples using the nanoplatform.

Multi-Color-Emissive Magneto-Luminescent Nanoarchitectures for Targeted Identification of Heterogeneous Exosomes Associated with Lung Cancer Metastasis.

Due to the lack of early detection before metastasis and failure of current therapy to cure the disease, lung cancer contributes to the highest cancer-related mortality worldwide. Tenascin C (TNC) (+) exosomes promote metastasis, amphiregulin (AREG) (+) exosomes are associated with chemotherapy resistance, and programmed cell death ligand-1 (PDL-1) (+) exosomes are associated with immunotherapy resistance, and they are emerging as biomarkers in clinics. However, due to heterogeneity, rapid isolation and multiplex detection of these exosomes are challenging. Herein, we report the design of an antibody-conjugated multi-color (orange, yellow, and green)-emissive carbon dot (CD)-attached cobalt spinel ferrite (CoFe2O4)-based magneto-luminescent nanoarchitecture for targeted capturing and identification of TNC (+), AREG (+), and PDL-1(+) exosomes selectively and simultaneously from whole blood samples. More importantly, to capture and identify the targeted AREG (+) exosome from an infected whole-blood sample, an anti-AREG antibody-attached green (520 nm)-emissive CD-conjugated CoFe2O4 nanoparticle-based magnetic-green luminescence nanoarchitecture was developed. Similarly, an anti-PDL-1 antibody-attached orange (600 nm)-emissive CDs-based magnetic-orange luminescence nanoarchitecture has been produced to capture and identify the PDL-1 (+) exosome. Furthermore, an anti-TNC antibody-attached yellow (560 nm)-emissive CD-based magnetic-orange luminescent nanoarchitecture has been designed to capture and identify the TNC (+) exosome. Notably, our finding reveals that 100% TNC (+) exosomes can be captured and imaged selectively from an infected blood sample using an anti-TNC antibody-conjugated nanoarchitecture. In addition, 100% AREG (+) exosomes can be captured and imaged selectively using an anti-AREG antibody-conjugated nanoarchitecture. Moreover, 100% PDL-1 (+) exosomes can be captured and imaged selectively using an anti-PDL-1 antibody-conjugated nanoarchitecture. Furthermore, we have demonstrated that a multi-color-emissive nanoarchitecture can be used for capturing and imaging all three exosomes simultaneously.

Light-Induced Wavelength Dependent Self Assembly Process for Targeted Synthesis of Phase Stable 1D Nanobelts and 2D Nanoplatelets of CsPbI3 Perovskites.

Despite black cubic phase α-CsPbI3 nanocrystals having an ideal bandgap of 1.73 eV for optoelectronic applications, the phase transition from α-CsPbI3 to non-perovskite yellow δ-CsPbI3 phase at room temperature remains a major obstacle for commercial applications. Since γ-CsPbI3 is thermodynamically stable with a bandgap of 1.75 eV, which has great potential for photovoltaic applications, herein we report a conceptually new method for the targeted design of phase stable and near unity photoluminescence quantum yield (PLQY) two-dimensional (2D) γ-CsPbI3 nanoplatelets (NPLs) and one-dimensional (1D) γ-CsPbI3 nanobelts (NBs) by wavelength dependent light-induced assembly of CsPbI3 cubic nanocrystals. This article demonstrates for the first time that by varying the excitation wavelengths, one can design air stable desired 2D nanoplatelets or 1D nanobelts selectively. Our experimental finding indicates that 532 nm green light-driven self-assembly produces phase stable and highly luminescent γ-CsPbI3 NBs from CsPbI3 nanocrystals. Moreover, we show that a 670 nm red light-driven self-assembly process produces stable and near unity PLQY γ-CsPbI3 NPLs. Systematic time-dependent microscopy and spectroscopy studies on the morphological evolution indicates that the electromagnetic field of light triggered the desorption of surface ligands from the nanocrystal surface and transformation of crystallographic phase from α to γ. Detached ligands played an important role in determining the morphologies of final structures of NBs and NPLs from nanocrystals via oriented attachment along the [110] direction initially and then the [001] direction. In addition, XRD and fluorescence imaging data indicates that both NBs and NPLs exhibit phase stability for more than 60 days in ambient conditions, whereas the cubic phase α-CsPbI3 nanocrystals are not stable for even 3 days. The reported light driven synthesis provides a simple and versatile approach to obtain phase pure CsPbI3 for possible optoelectronic applications.

WO3 Nanowire-Attached Reduced Graphene Oxide-Based 1D-2D Heterostructures for Near-Infrared Light-Driven Synergistic Photocatalytic and Photothermal Inactivation of Multidrug-Resistant Superbugs.

The rapid emergence of superbugs which are resistant to existing antibiotics is becoming a huge global threat to public health, which demands the discovery of next-generation antibacterial agents for combating superbugs. Herein, we report the design of a two-dimensional (2D) reduced graphene oxide (r-GO) and one-dimensional (1D) WO3 nanowire-based photothermal-photocatalytic heterostructure for combating multiantibiotic-resistant Salmonella DT104, carbapenem-resistant Enterobacteriaceae Escherichia coli, and methicillin-resistant Staphylococcus aureus superbugs. In the presence of near-infrared (NIR) light, due to the generation of electrons and holes, the WO3-based heterostructure generates reactive oxygen species by photocatalytic reaction from water and oxygen, which kills superbugs. To enhance the photocatalytic superbug killing efficiency, r-GO has been used for suppressing the recombination of the photoinduced electron-hole pairs. Reported data show that NIR light-driven synergistic photocatalytic-photothermal processes can be used for 100% degradation of methylene blue using a heterostructure-based catalyst, and the photodegradation rate for the heterostructure is much better than the literature data for different types of WO3/GO-based nanocomposites. Experimentally, time-dependent antibacterial efficiency data reveals that the heterostructure can destroy 100% superbugs within 30 min of light exposure via a synergistic photothermal and photocatalytic mechanism, whereas the WO3 nanowire can kill around 35% superbugs only via photocatalytic action only and r-GO can kill 25% superbugs via photothermal action even after 30 min of exposure to light. Systematic time-dependent microscopy and spectroscopy studies reveal that the excellent antisuperbug activities for heterostructures are due to membrane damage, ATP, and DNA/RNA breakage. For possible real-life applications, sun light-based superbug inactivation shows 100% inactivation possible within 250 min of light exposure using 12 mg/mL heterostructures. The reported sun light-driven killing of superbugs provides a simple and versatile platform to combat drug-resistant superbugs.

Human ACE2 Peptide-Attached Plasmonic-Magnetic Heterostructure for Magnetic Separation, Surface Enhanced Raman Spectroscopy Identification, and Inhibition of Different Variants of SARS-CoV-2 Infections.

The emergence of Alpha, Beta, Gamma, Delta, and Omicron variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for several million deaths up to now. Because of the huge amount of vaccine escape mutations in the spike (S) protein for different variants, the design of material for combating SARS-CoV-2 is very important for our society. Herein, we report on the design of a human angiotensin converting enzyme 2 (ACE2) peptide-conjugated plasmonic-magnetic heterostructure, which has the capability for magnetic separation, identification via surface enhanced Raman spectroscopy (SERS), and inhibition of different variant SARS-CoV-2 infections. In this work, plasmonic-magnetic heterostructures were developed using the initial synthesis of polyethylenimine (PEI)-coated Fe3O4-based magnetic nanoparticles, and then gold nanoparticles (GNPs) were grown onto the surface of the magnetic nanoparticles. Experimental binding data between ACE2-conjugated plasmonic-magnetic heterostructures and spike-receptor-binding domain (RBD) show that the Omicron variant has maximum binding ability, and it follows Alpha < Beta < Gamma < Delta < Omicron. Our finding shows that, due to the high magnetic moment (specific magnetization 40 emu/g), bioconjugated heterostructures are capable of effective magnetic separation of pseudotyped SARS-CoV-2 bearing the Delta variant spike from an infected artificial nasal mucus fluid sample using a simple bar magnet. Experimental data show that due to the formation of huge "hot spots" in the presence of SARS-CoV-2, Raman intensity for the 4-aminothiolphenol (4-ATP) Raman reporter was enhanced sharply, which has been used for the identification of separated virus. Theoretical calculations using finite-difference time-domain (FDTD) simulation indicate that, due to the "hot spots" formation, a six orders of magnitude Raman enhancement can be observed. A concentration-dependent inhibition efficiency investigation using a HEK293T-human cell line indicates that ACE2 peptide-conjugated plasmonic-magnetic heterostructures have the capability of complete inhibition of entry of different variants and original SARS-CoV-2 pseudovirions into host cells.

Bio-Conjugated Magnetic-Fluorescence Nanoarchitectures for the Capture and Identification of Lung-Tumor-Derived Programmed Cell Death Lighand 1-Positive Exosomes.

As per the American Cancer Society, lung cancer is the leading cause of cancer-related death worldwide. Since the accumulation of exosomal programmed cell death ligand 1 (PD-L1) is associated with therapeutic resistance in programmed cell death 1 (PD-1) and PD-L1 immunotherapy, tracking PD-L1-positive (PD-L1 (+)) exosomes is very important for predicting anti-PD-1 and anti-PD-L1 therapy for lung cancer. Herein, we report the design of an anti-PD-L1 monoclonal antibody-conjugated magnetic-nanoparticle-attached yellow fluorescent carbon dot (YFCD) based magnetic-fluorescence nanoarchitecture for the selective separation and accurate identification of PD-L1-expressing exosomes. In this work, photostable YFCDs with a good photoluminescence quantum yield (23%) were synthesized by hydrothermal treatment. In addition, nanoarchitectures with superparamagnetic (28.6 emu/g), biocompatible, and selective bioimaging capabilities were developed by chemically conjugating the anti-PD-L1 antibody and YFCDs with iron oxide nanoparticles. Importantly, using human non-small-cell lung cancer H460 cells lines, which express a high amount of PD-L1 (+) exosomes, A549 lung cancer cells lines, which express a low amount of PD-L1 (+) exosomes, and the normal skin HaCaT cell line, which does not express any PD-L1 (+) exosomes, we demonstrate that nanoarchitectures are capable of effectively separating and tracking PD-L1-positive exosomes simultaneously. Furthermore, as a proof-of-concept of clinical setting applications, a whole blood sample infected with PD-L1 (+) exosomes was analyzed, and our finding shows that this nanoarchitecture holds great promise for clinical applications.

Blocking SARS-CoV-2 Delta Variant (B.1.617.2) Spike Protein Receptor-Binding Domain Binding with the ACE2 Receptor of the Host Cell and Inhibiting Virus Infections Using Human Host Defense Peptide-Conjugated Graphene Quantum Dots.

The emergence of double mutation delta (B.1.617.2) variants has dropped vaccine effectiveness against SARS-CoV-2 infection. Although COVID-19 is responsible for more than 5.4 M deaths till now, more than 40% of infected individuals are asymptomatic carriers as the immune system of the human body can control the SARS-CoV-2 infection. Herein, we report for the first time that human host defense neutrophil α-defensin HNP1 and human cathelicidin LL-37 peptide-conjugated graphene quantum dots (GQDs) have the capability to prevent the delta variant virus entry into the host cells via blocking SARS-CoV-2 delta variant (B.1.617.2) spike protein receptor-binding domain (RBD) binding with host cells' angiotensin converting enzyme 2 (ACE2). Experimental data shows that due to the binding between the delta variant spike protein RBD and bioconjugate GQDs, in the presence of the delta variant spike protein, the fluorescence signal from GQDs quenched abruptly. Experimental quenching data shows a nonlinear Stern-Volmer quenching profile, which indicates multiple binding sites. Using the modified Hill equation, we have determined n = 2.6 and the effective binding affinity 9 nM, which is comparable with the ACE2-spike protein binding affinity (8 nM). Using the alpha, beta, and gamma variant spike-RBD, experimental data shows that the binding affinity for the delta B.1.617.2 variant is higher than those for the other variants. Further investigation using the HEK293T-human ACE2 cell line indicates that peptide-conjugated GQDs have the capability for completely inhibiting the entry of delta variant SARS-CoV-2 pseudovirions into host cells via blocking the ACE2-spike protein binding. Experimental data shows that the inhibition efficiency for LL-37 peptide- and HNP1 peptide-attached GQDs are much higher than that of only one type of peptide-attached GQDs.

Bioconjugated Nanomaterial for Targeted Diagnosis of SARS-CoV-2.

Infectious diseases by pathogenic microorganisms are one of the leading causes of mortality worldwide. Healthcare and socio-economic development have been seriously affected for different civilizations because of bacterial and viral infections. According to the Centers for Disease Control and Prevention (CDC), pandemic in 1918 by the Influenza A virus of the H1N1 subtype was responsible for 50 to 100 million deaths worldwide. Similarly, the Asian flu pandemic in 1957, Hong Kong flu in 1968, and H1N1pdm09 flu pandemic in 2009 were responsible for more than 1 million deaths across the globe each time. As per the World Health Organization (WHO), the current pandemic by coronavirus disease 2019 (COVID-19) due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is responsible for more than 4.8 M death worldwide until now. Since the gold standard polymerase chain reaction (PCR) test is more time-consuming, the health care system cannot test all symptomatic and asymptomatic Covid patients every day, which is extremely important to tackle the outbreak. One of the significant challenges during the current pandemic is developing mass testing tools, which is critical to control the virus spread in the community. Therefore, it is highly desirable to develop advanced material-based approaches that can provide a rapid and accurate diagnosis of COVID-19, which will have the capability to save millions of human lives. Aiming for the targeted diagnosis of deadly virus, researchers have developed nanomaterials with various sizes, shapes, and dimensions. These nanomaterials have been used to identify biomolecules via unique optical, electrical, magnetic, structural, and functional properties, which are lacking in other materials. Despite significant progress, nanomaterial-based diagnosis of biomolecules is still facing several obstacles due to low targeting efficiency and nonspecific interactions. To overcome these problems, the bioconjugated nanoparticle has been designed via surface coating with polyethylene glycol (PEG) and then conjugated with antibodies, DNA, RNA, or peptide aptamers. Therefore, the current Account summarizes an overview of the recent advances in the design of bioconjugated nanomaterial-based approached as effective diagnosis of the SARS-CoV-2 virus and the SARS-CoV-2 viral RNA, antigen, or antibody, with a particular focus on our work and other's work related to this subject. First, we present how to tailor the surface functionalities of nanomaterials to achieve bioconjugated material for targeted diagnosis of the virus. Then we review the very recent advances in the design of antibody/aptamer/peptide conjugated nanostructure, which represent a powerful platform for naked-eye colorimetric detection via plasmonic nanoparticles. We then discuss nanomaterial-based surface-enhanced Raman scattering (SERS) spectroscopy, which has the capability for very low-level fingerprint identification of virus, antigen, and antibody via graphene, plasmonic nanoparticle, and heterostructure material. After that, we summarized about fluorescence and nanoparticle surface energy transfer (NSET)-based on specific identification of SARS-CoV-2 infections via CNT, quantum dots (QDs), and plasmonic nanoparticles. Finally, we highlight the merit and significant challenges of nanostructure-based tools in infectious diseases diagnosis. For the researchers who want to engage in the new development of bioconjugated material for our survival from the current and future pandemics, we hope that this Account will be helpful for generating ideas that are scientifically stimulating and practically challenging.

Water Triggered Synthesis of Highly Stable and Biocompatible 1D Nanowire, 2D Nanoplatelet, and 3D Nanocube CsPbBr3 Perovskites for Multicolor Two-Photon Cell Imaging.

Two-photon imaging in the near-infrared window holds huge promise for real life biological imaging due to the increased penetration depth. All-inorganic CsPbX3 nanocrystals with bright luminescence and broad spectral tunability are excellent smart probes for two-photon bioimaging. But, the poor stability in water is a well-documented issue for limiting their practical use. Herein, we present the development of specific antibody attached water-resistant one-dimensional (1D) CsPbBr3 nanowires, two-dimensional (2D) CsPbBr3 nanoplatelets, and three-dimensional (3D) CsPbBr3 nanocubes which can be used for selective and simultaneous two-photon imaging of heterogeneous breast cancer cells in the near IR biological window. The current manuscript reports the design of excellent photoluminescence quantum yield (PLQY), biocompatible and photostable 1D CsPbBr3 nanowires, 2D CsPbBr3 nanoplatelets, and 3D CsPbBr3 nanocubes through an interfacial conversion from zero-dimensional (0D) Cs4PbBr6 nanocrystals via a water triggered strategy. Reported data show that just by varying the amount of water, one can control the dimension of CsPbBr3 perovskite crystals. Time-dependent transition electron microscopy and emission spectra have been reported to find the possible pathway for the formation of 1D, 2D, and 3D CsPbBr3 nanocrystals from 0D Cs4PbBr6 nanocrystals. Biocompatible 1D, 2D, and 3D CsPbBr3 nanocrystals were developed by coating with amine-poly(ethylene glycol)-propionic acid. Experimental data show the water-driven design of 1D, 2D, and 3D CsPbBr3 nanocrystals exhibits strong single-photon PLQY of ∼66-88% as well as excellent two-photon absorption properties (σ2) of ∼8.3 × 105-7.1 × 104 GM. Furthermore, reported data show more than 86% of PL intensity remains for 1D, 2D, and 3D CsPbBr3 nanocrystals after 35 days under water, and they exhibit excellent photostability of keeping 99% PL intensity after 3 h under UV light. The current report demonstrates for the first time that antibody attached 1D and 2D perovskites have capability for simultaneous two-photon imaging of triple negative breast cancer cells and human epidermal growth factor receptor 2 positive breast cancer cells. CsPbBr3 nanocrystals exhibit very high two-photon absorption cross-section and good photostability in water, which are superior to those of commonly used organic probes (σ2 = 11 GM for fluorescein), and therefore, they have capability to be a better probe for bioimaging applications.

Aptamer Conjugated Gold Nanostar-Based Distance-Dependent Nanoparticle Surface Energy Transfer Spectroscopy for Ultrasensitive Detection and Inactivation of Corona Virus.

The ongoing outbreak of the coronavirus infection has killed more than 2 million people. Herein, we demonstrate that Rhodamine 6G (Rh-6G) dye conjugated DNA aptamer-attached gold nanostar (GNS)-based distance-dependent nanoparticle surface energy transfer (NSET) spectroscopy has the capability of rapid diagnosis of specific SARS-CoV-2 spike recombinant antigen or SARS-CoV-2 spike protein pseudotyped baculovirus within 10 min. Because Rh-6G-attached single-stand DNA aptamer wrapped the GNS, 99% dye fluorescence was quenched because of the NSET process. In the presence of spike antigen or virus, the fluorescence signal persists because of the aptamer-spike protein binding. Specifically, the limit of detection for the NSET assay has been determined to be 130 fg/mL for antigen and 8 particles/mL for virus. Finally, we have demonstrated that DNA aptamer-attached GNSs can stop virus infection by blocking the angiotensin-converting enzyme 2 (ACE2) receptor binding capability and destroying the lipid membrane of the virus.

Mixed-Dimensional Heterostructure Material-Based SERS for Trace Level Identification of Breast Cancer-Derived Exosomes.

Raman spectroscopy has capability for fingerprint molecular identification with high sensitivity if weak Raman scattering signal can be enhanced by several orders of magnitudes. Herein, we report a heterostructure-based surface-enhanced Raman spectroscopy (SERS) platform using 2D graphene oxide (GO) and 0D plasmonic gold nanostar (GNS), with capability of Raman enhancement factor (EF) in the range of ∼1010 via light-matter and matter-matter interactions. The current manuscript reveals huge Raman enhancement for heterostructure materials occurring via both electromagnetic enhancement mechanism though plasmonic GNS nanoparticle (EF ∼107) and chemical enhancement mechanism through 2D-GO material (EF ∼102). Finite-difference time-domain (FDTD) simulation data and experimental investigation indicate that GNS allows light to be concentrated into nanoscale "hotspots" formed on the heterostructure surface, which significantly enhanced Raman efficiency via a plasmon-exciton light coupling process. Notably, we have shown that mixed-dimensional heterostructure-based SERS can be used for tracking of cancer-derived exosomes from triple-negative breast cancer and HER2(+) breast cancer with a limit of detection (LOD) of 3.8 × 102 exosomes/mL for TNBC-derived exosomes and 4.4 × 102 exosomes/mL for HER2(+) breast cancer-derived exosomes.

2D and Heterostructure Nanomaterial Based Strategies for Combating Drug-Resistant Bacteria.

In the last three decades, there has been a huge increase in the number of antibiotic-resistant bacterial strains, which is becoming a serious threat to public health. Since the discovery of new effective antibiotics has dramatically decreased in last ten years, there are huge initiatives to develop new antimicrobial approaches to fight drug-resistant bacterial infections. In the last decade, a new nanoparticle-based tool has emerged to combat deadly bacterial infections, which may overcome the barriers faced by antibiotic resistance. The current mini-review highlights recent reports on two-dimensional (2D) graphene oxide (GO), 2D transition metal dichalcogenides (TMD), 2D MXenes, and 2D heterostructure material-based approaches to tackle bacteria. Notably, we discuss the major design criteria which have been used to develop novel antimicrobial 2D and heterostructure materials to eliminate bacterial infections. Next, details on the various mechanisms underlying antibacterial activity for 2D and heterostructure materials such as physical/mechanical damage, lipid extraction, oxidative stress, and photothermal/photodynamic effects have been discussed. Finally, we highlight the promises, major challenges, and prospects of nanomaterial-based approaches to combat multidrug-resistant bacterial infections.

Development of Human Host Defense Antimicrobial Peptide-Conjugated Biochar Nanocomposites for Combating Broad-Spectrum Superbugs.

Infectious diseases by multidrug-resistant superbugs, which cannot be cured using commercially available antibiotics, are the biggest threat for our society. Due to the lack of discovery of effective antibiotics in the last two decades, there is an urgent need for the design of new broad-spectrum antisuperbug biomaterials. Herein, we report the development of antisuperbug nanocomposites using human host defense antimicrobial peptide-conjugated biochar. To develop an economically viable technology, biochar, a carbon-rich material from naturally abundant resource, has been used. For combating broad-spectrum superbugs, a nanocomposite has been designed by combining biochar with α-defensin human neutrophil peptide-1 (HNP-1), human ß-defensin-1 (hBD-1), and human cathelicidin LL-37 antimicrobial peptide. The designed three-dimensional (3D) nanocomposites with pore size between 200 and 400 nm have been used as channels for water passage and captured superbugs. The reported data demonstrated that antimicrobial nanocomposite can be used for efficient capture and eradication of Gram-negative carbapenem-resistant Enterobacteriaceae (CRE) Escherichia coli (E. coli) and Klebsiella pneumoniae (KPN) superbugs, as well as Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) superbugs. Possible mechanisms for broad-spectrum antisuperbug activities using hydrogel have been discussed.

Designing Highly Crystalline Multifunctional Multicolor Luminescence Nanosystem for Tracking Breast Cancer Heterogeneity.

Breast tumor heterogeneity is responsible for the death of ~ 40,000 women in 2017 in USA. Triple-negative breast cancers (TNBCs) are very aggressive and it is the only breast cancer subgroup still lacking effective therapeutic. As a result, early stage detection of TNBC is vital and it will have huge significant in the clinics. Driven by the need, here we report the design of highly crystalline antibody-conjugated multifunctional multicolor luminescence nanosystem derived from naturally available popular tropical fruits mango and prune, which have capability to track breast cancer heterogeneity via selective separation and accurate identification of TNBC and HER-2 (+) or ER/PR (+) breast cancer cells selectively and simultaneously. A detailed synthesis and characterization of multifunctional multicolor nanosystems from tropical fruits has been reported. Experimental results show that by changing the fruits, multicolor luminescent carbon dots (LCDs) can be developed and is mainly due to the formation of highly crystalline nano dots with different heavy metal doping and also due to the presence of different types of surface functional groups. Experimental data presented show that multifunctional multicolor nanoprobe can be used for highly selective and simultaneous capturing of targeted TNBCs, HER2(+) or ER(+) breast cancer cells and the capture efficiency can be as high as 98%. Reported data indicate that multicolor fluorescence imaging can be used for mapping hetergenous breast cancer cells simultaneously, and it can distinguish targeted TNBCs from non-targeted HER-2 (+) or ER/PR (+) breast cancer. Our finding suggests excellent possibility of designing multicolor nanosystems from natural fruits for tracking cancer heterogeneity in clinics.

Giant Chemical and Excellent Synergistic Raman Enhancement from a 3D MoS2-x O x -Gold Nanoparticle Hybrid.

Raman spectroscopy fingerprinting features many technological applications. For this purpose, the weak Raman signals need to be boosted dramatically by surface-enhanced Raman spectroscopy (SERS), which provides immense Raman enhancement via plasmonic and chemical mechanisms (CM). In this manuscript, we reveal the giant chemical as well as extremely high SERS enhancement from a three-dimensional MoS2-x O x -gold nanoparticle (GNP) hybrid, which has capability for ultrasensitive label-free sensing of chemical and biological molecules. Notably, reported data show that the chemical enhancement for the MoS2-x O x surface is ∼105, which is comparable with the plasmonic enhancement factor (EF) by GNP. Reported data show that the total Raman EF is ∼1013 from the GNP-MoS2-x O x hybrid. Intriguingly, combined experimental and theoretical finite difference time domain stimulation modeling findings show that the synergistic effect of electromagnetic mechanism and CM is responsible for huge SERS enhancement. Experimental results demonstrate that a proposed hybrid SERS platform can be used for fingerprint sensing of different multiple drug resistance bacteria at 5 cfu/mL concentration. Importantly, the current manuscript provides a good strategy for manipulating the SERS sensitivity to 13 orders of magnitude, which is instrumental for next-generation technological applications of Raman spectroscopy.

Antimicrobial Peptide-Conjugated MoS2-Based Nanoplatform for Multimodal Synergistic Inactivation of Superbugs.

Development of new antibacterial therapeutic materials is becoming increasingly urgent due to the huge threat of superbugs, which are responsible for more than half of a million deaths each year in this world. Here, we report the development of a novel nanobiomaterial based on a melittin antimicrobial peptide (AMP)-attached transition metal dichalcogenide MoS2-based theranostic nanoplatform. The reported nanoplatform has a capability for targeted identification and synergistic inactivation of 100% multidrug-resistant superbugs by a combined photo thermal therapy (PTT), photodynamic therapy (PDT), and AMP process. A novel approach for the design of a melittin antimicrobial peptide-attached MoS2-based nanoplatform is reported, which emits a very bright and photo stable fluorescence. It also generates heat as well as reactive oxygen species (ROS) in the presence of 670 nm near-infrared light, which allows it to be used as a PTT and PDT agent. Due to the presence of AMP, multifunctional AMP exhibits a significantly improved antibacterial activity for superbugs via a multimodal synergistic killing mechanism. Reported data demonstrate that nanoplatforms are capable of identification of multidrug-resistant superbugs via luminescence imaging. Experimental results show that it is possible to kill only ∼45% of superbugs via a MoS2 nanoplatform based on PTT and PDT processes together. On the other hand, killing less than 10% of superbugs is possible using melittin antimicrobial peptide alone, whereas 100% of methicillin-resistant Staphylococcus aureus (MRSA), drug-resistant Escherichia coli (E. coli), and drug-resistant Klebsiella pneumoniae (KPN) superbugs can be killed using antimicrobial peptide-attached MoS2 QDs, via a synergistic killing mechanism. Mechanisms for possible synergistic killing of multidrug-resistant superbugs have been discussed.

Water-Soluble and Bright Luminescent Cesium-Lead-Bromide Perovskite Quantum Dot-Polymer Composites for Tumor-Derived Exosome Imaging.

Cesium-lead-halide perovskite quantum dots (PQDs) are a highly promising class of the next-generation optical material for bioimaging applications. Herein, we present a nanocomposite strategy for the design of water-soluble, highly luminescence CsPbBr3 PQD nanocomposites without modifying the crystal symmetry and photoluminescence (PL) property. Water-soluble PQDs are reproducibly synthesized via encapsulating CsPbBr3 PQDs with polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (PS-PEB-PS) and poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol (PEG-PPG-PEG). In the reported design, the polystyrene triblock polymers strongly interact with the hydrophobic parts of PQDs, and the water-soluble PEG moiety acts as a protection layer to effectively prevent degradation of PQDs in water. The outer shell PEG layer also helps to develop biocompatible PQDs. Reported data indicate that encapsulating CsPbBr3 PQDs with a polymer helps to improve the photoluminescence quantum yield (PLQY) from 83% to 88%, which may be due to a decrease in the surface defects after the effective polymer coating. Experimental data show that the PL intensity from CsPbBr3 PQD nanocomposites remains unchanged even after 30 days of exposure in air. Similarly, reported data indicate that nanocomposites retain their luminescence properties in water for the first 8 days and then decrease slowly to 60% of its initial PL intensity after one month. On the other hand, the PL emission for the PQD without polymer encapsulation is completely quenched within a few hours. Exosomes are a highly promising avenue for accessing tumor type and stage and monitoring cancer treatment response. Reported data reveal that anti-CD63 antibody-attached PQD nanocomposites are capable of tracking triple-negative MDA-MB-231 breast tumor-derived exosomes via binding using anti-CD63 antibody and selective green luminescence imaging using PQD nanocomposites.

Multifunctional hybrid graphene oxide for circulating tumor cell isolation and analysis.

Even in 21st century, >90% cancer-associated deaths are caused by metastatic disease. Circulating tumor cells (CTCs), which circulate in the blood stream after release from primary tumors, extravasate and form fatal metastases in different organs. Several clinical trials indicate that CTCs can be used as a liquid biopsy of tumors for early diagnosis of cancers. Since CTCs are extremely rare and exhibit heterogeneous biology due to epithelial-mesenchymal transition (EMT), oncologists continue to face enormous challenges in using CTCs as a true "liquid biopsy" for cancer patients. Recent advancements in nanoscience allow us to design nano-architectures with the capability of targeted CTCs isolation and identification. In the current review, we discuss contribution from different groups on the development of graphene oxide based nanoarchitecture for effective isolation and accurate identification of CTCs from whole blood. In the last few years, using zero-dimensional (0D), two dimensional (2D) and three dimensional (3D) multifunctional hybrid graphene oxide (GO), different types of nanoarchitectures have been designed. These nanoarchitectures represent a highly powerful platform for CTC diagnosis. We discuss the major design criteria that have been used to develop hybrid GO nanoarchitectures for selective capture and accurate identification of heterogeneous CTCs from whole blood. At the end, we conclude with the promises, major challenges, and prospect to clinically translate the identification of CTCs using GO based nanotechnology.

Fluorescent, Magnetic Multifunctional Carbon Dots for Selective Separation, Identification, and Eradication of Drug-Resistant Superbugs.

The emergence of drug-resistant superbugs remains a major burden to society. As the mortality rate caused by sepsis due to superbugs is more than 40%, accurate identification of blood infections during the early stage will have a huge significance in the clinical setting. Here, we report the synthesis of red/blue fluorescent carbon dot (CD)-attached magnetic nanoparticle-based multicolor multifunctional CD-based nanosystems, which can be used for selective separation and identification of superbugs from infected blood samples. The reported data show that multifunctional fluorescent magneto-CD nanoparticles are capable of isolating Methicillin-resistant Staphylococcus aureus (MRSA) and Salmonella DT104 superbug from whole blood samples, followed by accurate identification via multicolor fluorescence imaging. As multidrug-resistant (MDR) superbugs are resistant to antibiotics available in the market, this article also reports the design of antimicrobial peptide-conjugated multicolor fluorescent magneto-CDs for effective separation, accurate identification, and complete disinfection of MDR superbugs from infected blood. The reported data demonstrate that by combining pardaxin antimicrobial peptides, magnetic nanoparticles, and multicolor fluorescent CDs into a single system, multifunctional CDs represent a novel material for efficient separation, differentiation, and eradication of superbugs. This material shows great promise for use in clinical settings.