Plasmonic Au@Ag Core-Shell Nanoisland Film for Photothermal Inactivation and Surface-Enhanced Raman Scattering Detection of Bacteria.

Plasmonic metal nanomaterials have been extensively investigated for their utilizations in biomedical sensing and treatment. In this study, plasmonic Au@Ag core-shell nanoisland films (Au@AgNIFs) were successfully grown onto a glass substrate using a seed-mediated growth procedure. The nanostructure of the Au@AgNIFs was confirmed through scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and atomic force microscopy (AFM). The UV-Vis spectra of the Au@AgNIFs exhibited a broad absorption in the visible range from 300 to 800 nm because of the surface plasmon absorption. Under simulated sunlight exposure, the temperature of optimal Au@AgNIF was increased to be 66.9 °C to meet the requirement for photothermal bacterial eradication. Furthermore, the Au@AgNIFs demonstrated a consistent photothermal effect during the cyclic on/off exposure to light. For photothermal therapy, the Au@AgNIFs revealed superior efficiency in the photothermal eradication of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). With their unique nanoisland nanostructure, the Au@AgNIFs exhibited excellent growth efficiency of bacteria in comparison with that of the bare glass substrate. The Au@AgNIFs were also validated as a surface-enhanced Raman scattering (SERS) substrate to amplify the Raman signals of E. coli and S. aureus. By integrating photothermal therapy and SERS detection, the Au@AgNIFs were revealed to be a potential platform for bacterial theranostics.

Zebrafish Insights into Nanomaterial Toxicity: A Focused Exploration on Metallic, Metal Oxide, Semiconductor, and Mixed-Metal Nanoparticles.

Nanomaterials are widely used in various fields, and ongoing research is focused on developing safe and sustainable nanomaterials. Using zebrafish as a model organism for studying the potentially toxic effects of nanomaterials highlights the importance of developing safe and sustainable nanomaterials. Studies conducted on nanomaterials and their toxicity and potential risks to human and environmental health are vital in biomedical sciences. In the present review, we discuss the potential toxicity of nanomaterials (inorganic and organic) and exposure risks based on size, shape, and concentration. The review further explores various types of nanomaterials and their impacts on zebrafish at different levels, indicating that exposure to nanomaterials can lead to developmental defects, changes in gene expressions, and various toxicities. The review also covers the importance of considering natural organic matter and chorion membranes in standardized nanotoxicity testing. While some nanomaterials are biologically compatible, metal and semiconductor nanomaterials that enter the water environment can increase toxicity to aquatic creatures and can potentially accumulate in the human body. Further investigations are necessary to assess the safety of nanomaterials and their impacts on the environment and human health.

Systematic designs of single metal compounds synthesized using ammonia fluoride-based complex as structure directing agents for energy storage.

Tailoring morphology and composition of metal organic frameworks (MOF) can improve energy storage by establishing high surface area, large porosity and multiple redox states. Structure directing agents (SDA) is functional of designing surface properties of electroactive materials. Ammonium fluoride has functional abilities for designing MOF derivatives with excellent energy storage abilities. Systematic design of MOF derivatives using ammonia fluoride-based complex as SDA can essentially create efficient electroactive materials. Metal species can also play significant roles on redox reactions, which are the main energy storage mechanism for battery-type electrodes. In this work, 2-methylimidazole, two novel SDAs of NH4BF4 and NH4HF2, and six metal species of Al, Mn, Co, Ni, Cu and Zn are coupled to synthesize MOF derivatives for energy storage. Metal species-dependent compositions including hydroxides, oxides, and hydroxide nitrates are observed. The nickel-based derivative (Ni-HBF) shows the highest specific capacitance (CF) of 698.0F/g at 20 mV/s, due to multiple redox states and advanced flower-like surface properties. The diffusion and capacitive-control contributions of MOF derivatives are also analyzed. The battery supercapacitor hybrid with Ni-HBF electrode shows a maximum energy density of 27.9 Wh/kg at 325 W/kg. The CF retention of 170.9% and Coulombic efficiency of 93.2% are achieved after 10,000 cycles.

Could combined rapid diagnostic testing for malaria and c-reactive protein be helpful for the diagnosis and management of febrile illnesses in children under-5 years of age in rural Burkina Faso?

BACKGROUND: Febrile illnesses are among the most important reasons for medical consultation in sub-Saharan Africa and are frequently treated with antimicrobials due to the unavailability of appropriate diagnostic tools. This practice leads to antimicrobial resistance, with increasing mortality and morbidity as result. One of the few accessible diagnostic tools available in low resource settings is malaria rapid diagnostic tests (mRDTs) which contributed to reducing the over-prescription of anti-malarials, but cannot guide antibiotic prescriptions. To circumvent this problem, we explored whether combined testing with mRDT and c-reactive protein (CRP) could improve the diagnosis of febrile illnesses and subsequent prescription of antibiotics. METHODS: Clinical specimens (blood, stool and urine) collected from 396 febrile children (axillary temperature of ≥ 37.5 °C) were analyzed with rapid diagnostic tests (malaria and CRP) and microbiology culture to establish the possible cause of fever. Actual antimicrobial prescriptions given to the children were compared with those that could be given based on combined CRP-malaria testing. RESULTS: In total, 68.7% (272/396) of malaria cases were diagnosed by mRDT-Pf-HRP-2. CRP test was positive in 84.3% (334/396) of the children, but bacterial infections were confirmed in 12.4% (49/396) of them. A possible cause of fever could not be established in 20.5% (81/396) of cases. Based on the diagnostic practice in place, 265 of the children with a positive mRDT-Pf-HRP-2 received anti-malarial treatment. Furthermore, 89.5% (111/124) of negative mRDT results received antibiotic treatment and 37.1% (46/124) received antimalarial treatment. Of these 124 cases, 80 had positive CRP tests and 44 negative CRP tests. If the results of CRP testing are considered, 44 CRP/mRDT negative children would not get antibiotic treatment, resulting in a 35.5% reduction in antibiotic prescriptions. However, 2 cases with a bacterial infection would be denied appropriate treatment. CONCLUSION: Combining mRDT-PfHRP2 with CRP testing is particularly useful in children for whom both tests are negative as it results in a reduction of antibiotics prescriptions. However, there is a risk to miss potential severe bacterial infections and a close follow-up of these cases is strongly recommended.

Haptoglobin-Conjugated Gold Nanoclusters as a Nanoantibiotic to Combat Bacteremia.

Gold nanoclusters have revealed great potential as nanoantibiotics due to their superior chemical and physical characteristics. In this study, a peptide with 83 amino acids derived from haptoglobin was utilized as a surface ligand to synthesize gold nanoclusters via a facile hydrothermal approach. Characterization of the structural and optical properties demonstrated the successful synthesis of derived haptoglobin-conjugated gold nanoclusters. The spherical derived haptoglobin-conjugated gold nanoclusters exhibited a (111) plane of cubic gold and an ultra-small size of 3.6 ± 0.1 nm. The optical properties such as ultraviolet-visible absorption spectra, X-ray photoelectron spectroscopy spectra, fluorescence spectra, and Fourier transform infrared spectra also validated the successful conjugation between the derived haptoglobin peptide and the gold nanoclusters surface. The antibacterial activity, reactive oxygen species production, and antibacterial mechanisms of derived haptoglobin-conjugated gold nanoclusters were confirmed by culturing the bacterium Escherichia coli with hemoglobin to simulate bacteremia. The surface ligand of the derived haptoglobin peptide of derived haptoglobin-conjugated gold nanoclusters was able to conjugate with hemoglobin to inhibit the growth of Escherichia coli. The derived haptoglobin-conjugated gold nanoclusters with an ultra-small size also induced reactive oxygen species production, which resulted in the death of Escherichia coli. The superior antibacterial activity of derived haptoglobin-conjugated gold nanoclusters can be attributed to the synergistic effect of the surface ligand of the derived haptoglobin peptide and the ultra-small size. Our work demonstrated derived haptoglobin-conjugated gold nanoclusters as a promising nanoantibiotic for combating bacteremia.

Ligand Incorporating Sequence-dependent ZIF67 Derivatives as Active Material of Supercapacitor: Competition between Ammonia Fluoride and 2-Methylimidazole.

The zeolitic imidazolate framework 67 (ZIF67) derivative is a potential active material of supercapacitors (SC), owing to high specific surface area and porosity and possible formation of cobalt compounds. A novel ZIF67 derivative is synthesized using a one-step solution process with cobalt precursor 2-methylimidazole (2-Melm) and ammonia fluoride in our previous work. Due to its facile synthesis and excellent electrocapacitive behavior, it is crucial to understand the competition between ammonia fluoride and 2-Melm on forming derivatives with cobalt ions and to create more efficient ZIF67 derivatives for charge storage. In this work, several ZIF67 derivatives are designed using a one-step solution process with 2-Melm and ammonia fluoride incorporated in different sequences. The reaction durations for a single ligand and two ligands are controlled. The largest capacity of 176.33 mAh/g corresponding to the specific capacitance of 1057.99 F/g is achieved for the ZIF67 derivative electrode prepared by reacting ammonia fluoride and a cobalt precursor for 0.5 h and then incorporating 2-Melm for another 23.5 h of reaction (NM0.5). This derivative composed of highly conductive CoF2, NiF2, Co(OH)F, and Ni(OH)F presents high specific surface area and porosity. The relevant SC presents a maximum energy density of 19.5 Wh/kg at 430 W/kg, a capacity retention of 92%, and Coulombic efficiency of 96% in 10000 cycles.

Lipid-Based Nanomaterials for Drug Delivery Systems in Breast Cancer Therapy.

Globally, breast cancer is one of the most prevalent diseases, inducing critical intimidation to human health. Lipid-based nanomaterials have been successfully demonstrated as drug carriers for breast cancer treatment. To date, the development of a better drug delivery system based on lipid nanomaterials is still urgent to make the treatment and diagnosis easily accessible to breast cancer patients. In a drug delivery system, lipid nanomaterials have revealed distinctive features, including high biocompatibility and efficient drug delivery. Specifically, a targeted drug delivery system based on lipid nanomaterials has inherited the advantage of optimum dosage and low side effects. In this review, insights on currently used potential lipid-based nanomaterials are collected and introduced. The review sheds light on conjugation, targeting, diagnosis, treatment, and clinical significance of lipid-based nanomaterials to treat breast cancer. Furthermore, a brighter side of lipid-based nanomaterials as future potential drug delivery systems for breast cancer therapy is discussed.

Novel design of Sulfur-doped nickel cobalt layered double hydroxide and polypyrrole nanotube composites from zeolitic imidazolate Framework-67 as efficient active material of battery supercapacitor hybrids.

Nickel and cobalt layered double hydroxide (NiCo-LDH) has large specific surface area and interlayer spacing, multiple redox states and high ion-exchange capability, but poor electrical conductivity, severe agglomerations and structural defect restrict energy storage ability of NiCo-LDH as active materiel of battery supercapacitor hybrids (BSH). In this study, it is the first time to design sulfur-doped NiCo-LDH and polypyrrole nanotubes composites (NiCo-LDH-S/PNTs) from zeolitic imidazolate framework-67 (ZIF-67) as the efficient active material of BSH using electrospinning and hydrothermal processes. Effects of sulfur doping amounts are investigated. The one-dimensional hollow polypyrrole decorated with NiCo-LDH-S sheets with high aspect ratio provides straight charge-transfer routes and abundant contacts with electrolyte. The highest specific capacitance (CF) of 1936.3 F/g (specific capacity of 322.8 mAh/g) is achieved for the NiCo-LDH-S/PNTs with sulfur doping amount of 7% at 10 mV/s. The BSH comprising graphene LDH negative electrode and NiCo-LDH-S/PNTs positive electrode shows the maximum energy density of 16.28 Wh/kg at 650 W/kg. The CF retention of 74% and Coulombic efficiency of 90% are also achieved after 8000 charge/discharge cycles.

Enhanced photocurrent density for photoelectrochemical catalyzing water oxidation using novel W-doped BiVO4 and metal organic framework composites.

Doping heteroatoms and decorating co-catalyst are intensively applied to improve photocatalytic ability of BiVO4. In this study, it is the first time to design W-doped BiVO4 coupling MIL-101(Fe) as photocatalyst for water oxidation using electrodeposition and hydrothermal processes. Similar system with Mo as dopant has been reported, but the dopant plays important roles on electrochemical performance. It is worthy to study the efficient system with different dopant. Doping amount of W is optimized to achieve high carrier density without creating serious recombination sites. MIL-101(Fe) is decorated on W-doped BiVO4 to suppress surface recombination, create accessible active sites and improve water oxidation kinetics. Optimized W-doped BiVO4/MIL-101(Fe) electrode shows a high photocurrent density of 4.00 mA/cm2 at 1.23 V versus reversible hydrogen electrode (VRHE) under air mass 1.5-global simulated light illumination without hole scavenger in electrolyte, due to large electrochemical surface area, high carrier density and small charge-transfer resistance. The W-doped BiVO4 and BiVO4 electrodes merely show photocurrent densities of 2.96 and 1.72 mA/cm2 at 1.23 VRHE, respectively. Photocurrent retention higher than 95.5% is obtained for W-doped BiVO4/MIL-101 (Fe) electrode under continuous illumination for 6300 s, suggesting lasting photocatalytic ability of this novel W-doped BiVO4/MIL-101(Fe) electrode.

Calcium Phosphate Nanoclusters for the Repair of Tooth Enamel Erosion.

The artificial repair of tooth enamel is still an urgent requirement because it has a complicated and well-arranged structure. Herein, calcium phosphate nanoclusters (CaP NCs) were synthesized, via a facile approach, for application in the repair of tooth enamel erosion. Structural and optical characterizations validated the successful preparation of spherical CaP NCs, with an average size of 2.1 ± 0.11 nm. By evaporating the ethanol and triethylamine (TEA) solvents, pure CaP was produced, which was further used to repair the tooth enamel. Simulated caries lesions were achieved via phosphoric acid etching to cause damage to enamel rods. After repair, the damaged enamel rods were directly covered with CaP. According to microhardness testing, after repair with CaP NCs, the hardness value of the tooth enamel with acid etching increased to a similar level to that of normal tooth enamel. The results of the microhardness test indicated that CaP NCs revealed great potential for repairing tooth enamel erosion. Our work demonstrates a promising potential for treating the early stage of tooth erosion with CaP NCs. Based on these findings, we believe that stable CaP NCs can be employed as a precursor for the tunable, effective repair of tooth enamel in the near future.

Design of novel self-assembled MXene and ZIF67 derivative composites as efficient electroactive material of energy storage device.

High surface area and tunable pore size are beneficial for metal organic frameworks (MOFs) as electroactive material of energy storage devices. Novel ZIF67 derivative proposed in our previous work, nickel cobalt fluoride coupled with ammonia ions (NCNF), is synthesized using ammonia fluoride to solve poor electrical conductivity of MOFs. MXene is commonly incorporated in pseudo-capacitive materials to enhance electrical conductivity and energy storage ability. In this study, it is the first time to design MXene and NCNF composites (MXene/NCNF) with different MXene amounts via incorporating MXene in growing process of NCNF. MXene and NCNF are combined via self-assembly in a simple room temperature solution process. The optimized MXene/NCNF electrode shows a higher specific capacitance of 1020.0 F g-1 (170.0 mAh g-1) than that of NCNF electrode (574.2 F g-1 and 95.7 mAh g-1) at 20 mV s-1, due to excellent surface properties of MXene/NCNF with conductive network of MXene and high electrocapacitive performance of NCNF. A symmetric energy storage device composed of the optimized MXene/NCNF electrodes presents outstanding cycling stability with Coulombic efficiency of 100% during whole cycling process and a high capacitance retention of 99% after 6000 cycles. Excellent electrochemical performance and simple synthesis of MXene/NCNF open new blueprints for designing novel electrocapacitive materials for electrochemical applications.

Novel direct growth of ZIF-67 derived Co3O4 and N-doped carbon composites on carbon cloth as supercapacitor electrodes.

Zeolitic imidazolate framework-67 (ZIF67) derivatives are considered as promising active materials for energy storage owing to the possible formation of cobalt oxide and N-doped graphite. Cobalt oxide has multiple redox states for generating redox reactions for charge storage, while N-doped graphite can provide high electrical conductivity for charge transfer. In this study, it is the first time to synthesize binder-free electrodes composed of cobalt oxide and N-doped graphite derived from ZIF67 on carbon cloth (CC) for supercapacitor (SC). Successive oxidation and carbonization along with additional coverage of ZIF67 derivatives are applied to synthesize ZIF67 derivatives composed of cobalt oxide, N-doped graphite and cobalt oxide/N-doped graphite composites with different layer compositions. The highest specific capacitance (CF) of 90.0F/g at 20 mV/s is obtained for the oxidized ZIF67/carbonized ZIF67/carbon cloth (O67/C67/CC) electrode, due to the large surface area and high electrical conductivity benefitted from preferable morphology and growing sequence of Co3O4 and N-doped graphite. The symmetric SC composed of O67/C67/CC electrodes shows the maximum energy density of 2.53 Wh/kg at the power density of 50 W/kg. Cycling stability with CF retention of 70% and Coulombic efficiency of 65% after 6000 times repeatedly charge/discharge process is also obtained for this symmetric SC.

Design of LiFePO4 and porous carbon composites with excellent High-Rate charging performance for Lithium-Ion secondary battery.

Lithium iron phosphate (LFP) is one of the promising cathode materials of lithium ion battery (LIB), but poor electrical conductivity restricts its electrochemical performance. Carbon coating can improve electrical conductivity of LFP without changing its intrinsic property. Uniform coating of carbon on LFP is significant to avoid charge congregation and unpreferable redox reactions. It is the first time to apply the commercial organic binder, Super P® (SP), as carbon source to achieve uniform coating on LFP as cathode material of LIB. The simple and economical mechanofusion method is firstly applied to coat different amounts of SP on LFP. The LIB with the cathode material of optimized SP-coated LFP shows the highest capacity of 165.6 mAh/g at 0.1C and 59.8 mAh/g at 10C, indicating its high capacity and excellent high-rate charge/discharge capability. SP is applied on other commercial LFP materials, M121 and M23, for carbon coating. Enhanced high-rate charge/discharge capabilities are also achieved for LIB with SP-coated M121 and M23 as cathode materials. This new material and technique for carbon coating is verified to be applicable on different LFP materials. This novel carbon coating method is expected to apply on other cathode materials of LIB with outstanding electrochemical performances.

Gold Nanorod-Decorated Metallic MoS2 Nanosheets for Synergistic Photothermal and Photodynamic Antibacterial Therapy.

Light-responsive nanocomposites have become increasingly attractive in the biomedical field for antibacterial applications. Visible-light-activated metallic molybdenum disulfide nanosheets (1T-MoS2 NSs) and plasmonic gold nanorods (AuNRs) with absorption at a wavelength of 808 nm were synthesized. AuNR nanocomposites decorated onto 1T-MoS2 NSs (MoS2@AuNRs) were successfully prepared by electrostatic adsorption for phototherapy applications. Based on the photothermal effect, the solution temperature of the MoS2@AuNR nanocomposites increased from 25 to 66.7 °C after 808 nm near-infrared (NIR) laser irradiation for 10 min. For the photodynamic effect, the MoS2@AuNR nanocomposites generated reactive oxygen species (ROS) under visible light irradiation. Photothermal therapy and photodynamic therapy of MoS2@AuNRs were confirmed against E. coli by agar plate counts. Most importantly, the combination of photothermal therapy and photodynamic therapy from the MoS2@AuNR nanocomposites revealed higher antibacterial activity than photothermal or photodynamic therapy alone. The light-activated MoS2@AuNR nanocomposites exhibited a remarkable synergistic effect of photothermal therapy and photodynamic therapy, which provides an alternative approach to fight bacterial infections.

Plasmonic Gold Nanoisland Film for Bacterial Theranostics.

Plasmonic nanomaterials have been intensively explored for applications in biomedical detection and therapy for human sustainability. Herein, plasmonic gold nanoisland (NI) film (AuNIF) was fabricated onto a glass substrate by a facile seed-mediated growth approach. The structure of the tortuous gold NIs of the AuNIF was demonstrated by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Based on the ultraviolet-visible spectrum, the AuNIF revealed plasmonic absorption with maximum intensity at 624 nm. With the change to the surface topography created by the NIs, the capture efficiency of Escherichia coli (E. coli) by the AuNIF was significantly increased compared to that of the glass substrate. The AuNIF was applied as a surface-enhanced Raman scattering (SERS) substrate to enhance the Raman signal of E. coli. Moreover, the plasmonic AuNIF exhibited a superior photothermal effect under irradiation with simulated AM1.5 sunlight. For photothermal therapy, the AuNIF also displayed outstanding efficiency in the photothermal killing of E. coli. Using a combination of SERS detection and photothermal therapy, the AuNIF could be a promising platform for bacterial theranostics.

Emerging Trends in Nanomaterials for Antibacterial Applications.

Around the globe, surges of bacterial diseases are causing serious health threats and related concerns. Recently, the metal ion release and photodynamic and photothermal effects of nanomaterials were demonstrated to have substantial efficiency in eliminating resistance and surges of bacteria. Nanomaterials with characteristics such as surface plasmonic resonance, photocatalysis, structural complexities, and optical features have been utilized to control metal ion release, generate reactive oxygen species, and produce heat for antibacterial applications. The superior characteristics of nanomaterials present an opportunity to explore and enhance their antibacterial activities leading to clinical applications. In this review, we comprehensively list three different antibacterial mechanisms of metal ion release, photodynamic therapy, and photothermal therapy based on nanomaterials. These three different antibacterial mechanisms are divided into their respective subgroups in accordance with recent achievements, showcasing prospective challenges and opportunities in clinical, environmental, and related fields.

Antibiotic susceptibility profile of bacterial isolates from febrile children under 5 years of age in Nanoro, Burkina Faso.

OBJECTIVES: Antibiotics efficacy is severely threatened due to emerging resistance worldwide, but there is a paucity of antibiotics efficacy data for the West African region in general. Therefore, this study aimed to determine the antibiotic susceptibility profile of bacterial isolated from febrile children under 5 years of age in Nanoro (Burkina Faso). METHODS: Blood, stool and urine samples were collected from 1099 febrile children attending peripheral health facilities and the referral hospital in Nanoro Health district. Bacterial isolates from these samples were assessed for their susceptibility against commonly used antibiotics by Kirby-Bauer method. RESULTS: In total, 141 bacterial isolates were recovered from 127 febrile children of which 65 from blood, 65 from stool and 11 from urine. Salmonella isolates were most frequently isolated and found to be highly resistant to ampicillin (70%; 56/80) and trimethoprim-sulphamethoxazole (65%; 52/80). Escherichia coli isolates showed a high resistance rate to trimethoprim-sulphamethoxazole (100%), ampicillin (100%), ciprofloxacin (71.4%; 10/14), amoxicillin-clavulanate (64.3%; 9/14), ceftriaxone (64.3%; 9/14) and gentamycin (50%; 7/14). Moreover, half of the E. coli isolates produced ß-lactamase suggesting multi-drug resistance against ß-lactam as well as non-ß-lactam antibiotics. Multi-drug resistance was observed in 54.6% (59/108) of the isolates, mainly Gram-negative bacteria. CONCLUSIONS: This study showed high resistance rates to common antibiotics used to treat bacterial infections in Nanoro. The work prompts the need to expand antibiotic resistance surveillance studies in Burkina Faso.

Facet-dependent gold nanocrystals for effective photothermal killing of bacteria.

Gold-based plasmonic nanocrystals have been extensively developed for noninvasive photothermal therapy. In this study, gold nanorods (AuNRs) with (200) plane and gold nanobipyramids (AuNBPs) with (111) plane were utilized as photothermal agents for noninvasive photothermal therapy. With longitudinal surface plasma bands at ~808 nm, both of AuNRs and AuNBPs revealed photothermal capability and reversibility of laser response under 808-nm near-infrared (NIR) laser irradiation. Moreover, AuNBPs with (111) plane exhibited higher photothermal performance than that of AuNRs with (200) plane under NIR laser irradiation. Density function theory (DFT) simulations revealed that water adsorption energy followed the order Au(111) < Au(100), indicating that the water was easily desorbed on the Au(111) surface for photothermal heating. For the photothermal therapy against Escherichia coli (E. coli), AuNBPs also exhibited higher efficiency compared to that of AuNRs under NIR laser irradiation. Combination of experimental photothermal therapy and DFT simulations demonstrated that AuNBPs with (111) plane were better photothermal agents than that of AuNRs with (100) plane.

Hemoglobin-Conjugated Gold Nanoclusters for Qualitative Analysis of Haptoglobin Phenotypes.

Designing a facile and rapid detection method for haptoglobin (Hp) phenotypes in human blood plasma is urgently needed to meet clinic requirements in hemolysis theranostics. In this work, a novel approach to qualitatively analyze Hp phenotypes was developed using a fluorescent probe of gold nanoclusters (AuNCs). Hemoglobin-conjugated (Hb)-AuNCs were successfully synthesized with blue-green fluorescence and high biocompatibility via one-pot synthesis. The fluorescence of Hb-AuNCs comes from the ligand-metal charge transfer between surface ligands of Hb and the gold cores with high oxidation states. The biocompatibility assays including cell viability and fluorescence imaging, demonstrated high biocompatibility of Hb-AuNCs. For the qualitative analysis, three Hp phenotypes in plasma, Hp 1-1, Hp 2-1, and Hp 2-2, were successfully discriminated according to changes in the fluorescence intensity and peak position of the maximum intensity of Hb-AuNCs. Our work provides a practical method with facile and rapid properties for the qualitative analysis of three Hp phenotypes in human blood plasma.

One-Pot Synthesis of Thiol-Modified Liquid Crystals Conjugated Fluorescent Gold Nanoclusters.

Gold nanoclusters (AuNCs) and liquid crystals (LCs) have shown great potential in nanobiotechnology applications due to their unique optical and structural properties. Herein, the hardcore of the 4-cyano biphenyl group for commonly used LCs of 4-cyano-4'-pentylbiphenyl (5CB) was utilized to synthesize 4'-(2-mercaptoethyl)-(1,1'-biphenyl)-4-carbonitrile (TAT-12) based on Suzuki coupling and Appel reaction. The structural and optical properties of thiol-modified TAT-12 LCs were demonstrated by nuclear magnetic resonance (NMR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy and differential scanning calorimetry (DSC). By one-pot synthesis, thiol-modified TAT-12 LCs were used as the ligands to prepare fluorescent gold nanoclusters (AuNCs@TAT-12) according to the Au-S bond between AuNCs and TAT-12. The spectra of UV-vis absorption and X-ray photoelectron spectroscopy (XPS) of AuNCs@TAT-12 indicated that the core of gold of AuNCs@TAT-12 exhibited high gold oxidation states. The fluorescence of AuNCs@TAT-12 was observed with a maximum intensity at ~352 nm coming from TAT-12 on AuNCs@TAT-12 and the fluorescence quantum yield of AuNCs@TAT-12 was calculated to be 10.1%. Furthermore, the fluorescence with a maximum intensity at ~448 nm was attributed to a ligand-metal charge transfer between the ligands of TAT-12 LCs and the core of AuNCs. The image of transmission electron microscopy (TEM) further demonstrated an approximately spherical shape of AuNCs@TAT-12 with an average size of 2.3 nm. A combination of UV-vis absorption spectra, XPS spectra, fluorescence spectra and TEM image, fluorescent AuNCs@TAT-12 were successfully synthesized via one-pot synthesis. Our work provides a practical approach to the synthesis of LCs conjugated AuNCs for future applications in nanobiotechnology.