Bright photon upconversion in LiYbF4:Tm3+@LiYF4 nanoparticles and their application for singlet oxygen generation and in immunoassay for SARS-CoV-2 nucleoprotein.

Photon upconversion is an intensively investigated phenomenon in the materials sciences due to its unique applications, mainly in biomedicine for disease prevention and treatment. This study reports the synthesis and properties of tetragonal LiYbF4:Tm3+@LiYF4 core@shell nanoparticles (NPs) and their applications. The NPs had sizes ranging from 18.5 to 23.7 nm. As a result of the energy transfer between Yb3+ and Tm3+ ions, the synthesized NPs show intense emission in the ultraviolet (UV) range up to 347 nm under 975 nm excitation. The bright emission in the UV range allows for singlet oxygen generation in the presence of hematoporphyrin on the surface of NPs. Our studies show that irradiation with a 975 nm laser of the functionalized NPs allows for the production of amounts of singlet oxygen easily detectable by Singlet Oxygen Sensor Green. The high emission intensity of NPs at 800 nm allowed the application of the synthesized NPs in an upconversion-linked immunosorbent assay (ULISA) for highly sensitive detection of the nucleoprotein from SARS-CoV-2, the causative agent of Covid-19. This article proves that LiYbF4:Tm3+@LiYF4 core@shell nanoparticles can be perfect alternatives for the most commonly studied upconverting NPs based on the NaYF4 host compound and are good candidates for biomedical applications.

Rapid screening of benzyl dodecyl dimethyl ammonium bromide co-metabolic degrading bacteria based on NIR hyperspectral imaging technology.

As a typical disinfectant, the use of benzyl dodecyl dimethyl ammonium bromide (BDAB) has dramatically increased since the emergence of SARS-CoV-2, posing a threat to environmental balance and human health. Screening BDAB co-metabolic degrading bacteria is required for efficient microbial degradation. Conventional methods for screening co-metabolic degrading bacteria are laborious and time-consuming, especially when the number of strains is large. This study aimed to develop a novel method for the rapid screening of BDAB co-metabolic degrading bacteria from the cultured solid medium using near-infrared hyperspectral imaging (NIR-HSI) technology. Based on NIR spectra, the concentration of BDAB in the solid medium can be well predicted by partial least squares regression (PLSR) models, non-destructively and rapidly, with Rc2 > 0.872 and Rcv2 > 0.870. The results show that the predicted BDAB concentrations decrease after degrading bacteria utilization, comparing with the regions where no degrading bacteria grew. The proposed method was applied to directly identify the BDAB co-metabolic degrading bacteria cultured on the solid medium, and two kinds of co-metabolic degrading bacteria RQR-1 and BDAB-1 were correctly identified. This method provides a high-efficiency method for screening BDAB co-metabolic degrading bacteria from a large number of bacteria.

Engineering highly efficient NIR-II FRET platform for Background-Free homogeneous detection of SARS-CoV-2 neutralizing antibodies in whole blood.

Förster or fluorescence resonance energy transfer (FRET) enables to probe biomolecular interactions, thus playing a vital role in bioassays. However, conventional FRET platforms suffer from limited sensitivity due to the low FRET efficiency and poor anti-interference of existing FRET pairs. Here we report a NIR-II (1000-1700 nm) FRET platform with extremely high FRET efficiency and exceptional anti-interference capability. This NIR-II FRET platform is established based on a pair of lanthanides downshifting nanoparticles (DSNPs) by employing Nd3+ doped DSNPs as an energy donor and Yb3+ doped DSNPs as an energy acceptor. The maximum FRET efficiency of this well-engineered NIR-II FRET platform reaches up to 92.2%, which is much higher than most commonly used ones. Owing to the all-NIR advantage (λex = 808 nm, λem = 1064 nm), this highly efficient NIR-II FRET platform exhibits extraordinary anti-interference in whole blood, and thus enabling background-free homogeneous detection of SARS-CoV-2 neutralizing antibodies in clinical whole blood sample with high sensitivity (limit of detection = 0.5 µg/mL) and specificity. This work opens up new opportunities for realizing highly sensitive detection of various biomarkers in biological samples with severe background interference.

Titelbild: Highly Twisted Conformation Thiopyrylium Photosensitizers for In Vivo Near Infrared‐II Imaging and Rapid Inactivation of Coronavirus (Angew. Chem. 13/2023)

The resulting NIR-II PS not only enables NIR-II image-guided in vivo pulmonary coronavirus photo-ablation but also demonstrates a facile approach for the development of NIR heavy-atom-free PSs. Keywords: Coronavirus Inactivation;Intersystem Crossing;NIR-II Imaging;Photosensitizer;Triplet State EN Coronavirus Inactivation Intersystem Crossing NIR-II Imaging Photosensitizer Triplet State 1 1 1 03/15/23 20230320 NES 230320 B The relationship b between molecular configuration and charge transfer processes in near-infrared-II (NIR-II) chromophores was studied, and subsequently instructed the engineering of an efficient NIR photosensitizer (PS), as reported by Wenbo Hu, Yuliang Xiao et al. in their Research Article (e202214875). The resulting NIR-II PS not only enables NIR-II image-guided in vivo pulmonary coronavirus photo-ablation but also demonstrates a facile approach for the development of NIR heavy-atom-free PSs. [Extracted from the article] Copyright of Angewandte Chemie is the property of John Wiley & Sons, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Cover Picture: Highly Twisted Conformation Thiopyrylium Photosensitizers for In Vivo Near Infrared‐II Imaging and Rapid Inactivation of Coronavirus (Angew. Chem. Int. Ed. 13/2023)

The resulting NIR-II PS not only enables NIR-II image-guided in vivo pulmonary coronavirus photo-ablation but also demonstrates a facile approach for the development of NIR heavy-atom-free PSs. Keywords: Coronavirus Inactivation;Intersystem Crossing;NIR-II Imaging;Photosensitizer;Triplet State EN Coronavirus Inactivation Intersystem Crossing NIR-II Imaging Photosensitizer Triplet State 1 1 1 03/15/23 20230320 NES 230320 B The relationship b between molecular configuration and charge transfer processes in near-infrared-II (NIR-II) chromophores was studied, and subsequently instructed the engineering of an efficient NIR photosensitizer (PS), as reported by Wenbo Hu, Yuliang Xiao et al. in their Research Article (e202214875). The resulting NIR-II PS not only enables NIR-II image-guided in vivo pulmonary coronavirus photo-ablation but also demonstrates a facile approach for the development of NIR heavy-atom-free PSs. [Extracted from the article] Copyright of Angewandte Chemie International Edition is the property of John Wiley & Sons, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Highly Twisted Conformation Thiopyrylium Photosensitizers for In Vivo Near Infrared‐II Imaging and Rapid Inactivation of Coronavirus

Despite significant effort, a majority of heavy‐atom‐free photosensitizers have short excitation wavelengths, thereby hampering their biomedical applications. Here, we present a facile approach for developing efficient near‐infrared (NIR) heavy‐atom‐free photosensitizers. Based on a series of thiopyrylium‐based NIR‐II (1000–1700 nm) dyads, we found that the star dyad HD with a sterically bulky and electron‐rich moiety exhibited configuration torsion and significantly enhanced intersystem crossing (ISC) compared to the parent dyad. The electron excitation characteristics of HD changed from local excitation (LE) to charge transfer (CT)‐domain, contributing to a ≈6‐fold reduction in energy gap (ΔEST), a ≈10‐fold accelerated ISC process, and a ≈31.49‐fold elevated reactive oxygen species (ROS) quantum yield. The optimized SP@HD‐PEG2K lung‐targeting dots enabled real‐time NIR‐II lung imaging, which precisely guided rapid pulmonary coronavirus inactivation.

Highly Twisted Conformation Thiopyrylium Photosensitizers for In Vivo Near Infrared-II Imaging and Rapid Inactivation of Coronavirus.

Despite significant effort, a majority of heavy-atom-free photosensitizers have short excitation wavelengths, thereby hampering their biomedical applications. Here, we present a facile approach for developing efficient near-infrared (NIR) heavy-atom-free photosensitizers. Based on a series of thiopyrylium-based NIR-II (1000-1700 nm) dyads, we found that the star dyad HD with a sterically bulky and electron-rich moiety exhibited configuration torsion and significantly enhanced intersystem crossing (ISC) compared to the parent dyad. The electron excitation characteristics of HD changed from local excitation (LE) to charge transfer (CT)-domain, contributing to a ≈6-fold reduction in energy gap (ΔEST ), a ≈10-fold accelerated ISC process, and a ≈31.49-fold elevated reactive oxygen species (ROS) quantum yield. The optimized SP@HD-PEG2K lung-targeting dots enabled real-time NIR-II lung imaging, which precisely guided rapid pulmonary coronavirus inactivation.

Coupling of NIR Spectroscopy and Chemometrics for the Quantification of Dexamethasone in Pharmaceutical Formulations.

Counterfeit or substandard drugs are pharmaceutical formulations in which the active pharmaceutical ingredients (APIs) have been replaced or ingredients do not comply with the drug leaflet. With the outbreak of the COVID-19 pandemic, fraud associated with the preparation of substandard or counterfeit drugs is expected to grow, undermining health systems already weakened by the state of emergency. Analytical chemistry plays a key role in tackling this problem, and in implementing strategies that permit the recognition of uncompliant drugs. In light of this, the present work represents a feasibility study for the development of a NIR-based tool for the quantification of dexamethasone in mixtures of excipients (starch and lactose). Two different regression strategies were tested. The first, based on the coupling of NIR spectra and Partial Least Squares (PLS) provided good results (root mean square error in prediction (RMSEP) of 720 mg/kg), but the most accurate was the second, a strategy exploiting sequential preprocessing through orthogonalization (SPORT), which led (on the external set of mixtures) to an R2pred of 0.9044, and an RMSEP of 450 mg/kg. Eventually, Variable Importance in Projection (VIP) was applied to interpret the obtained results and determine which spectral regions contribute most to the SPORT model.

Plasma-induced nanoparticle aggregation for stratifying COVID-19 patients according to disease severity.

Stratifying patients according to disease severity has been a major hurdle during the COVID-19 pandemic. This usually requires evaluating the levels of several biomarkers, which may be cumbersome when rapid decisions are required. In this manuscript we show that a single nanoparticle aggregation test can be used to distinguish patients that require intensive care from those that have already been discharged from the intensive care unit (ICU). It consists of diluting a platelet-free plasma sample and then adding gold nanoparticles. The nanoparticles aggregate to a larger extent when the samples are obtained from a patient in the ICU. This changes the color of the colloidal suspension, which can be evaluated by measuring the pixel intensity of a photograph. Although the exact factor or combination of factors behind the different aggregation behavior is unknown, control experiments demonstrate that the presence of proteins in the samples is crucial for the test to work. Principal component analysis demonstrates that the test result is highly correlated to biomarkers of prognosis and inflammation that are commonly used to evaluate the severity of COVID-19 patients. The results shown here pave the way to develop nanoparticle aggregation assays that classify COVID-19 patients according to disease severity, which could be useful to de-escalate care safely and make a better use of hospital resources.

Sensitively detecting antigen of SARS-CoV-2 by NIR-II fluorescent nanoparticles.

Early detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is an efficient way to prevent the spread of coronavirus disease 2019 (COVID-19). Detecting SARS-CoV-2 antigen can be rapid and convenient, but it is still challenging to develop highly sensitive methods for effective diagnosis. Herein, a lateral flow assay (LFA) based on fluorescent nanoparticles emitting in the second near-infrared (NIR-II) window is developed for sensitive detection of SARS-CoV-2 antigen. Benefiting from the NIR-II fluorescence with high penetration and low autofluorescence, such NIR-II based LFA allows enhanced signal-to-background ratio, and the limit of detection is down to 0.01 ng·mL-1 of SARS-CoV-2 antigen. In the clinical swab sample tests, the NIR-II LFA outperforms the colloidal gold LFA with higher overall percent agreement with the polymerase chain reaction test. The clinical samples with low antigen concentrations (∼ 0.015-∼ 0.068 ng·mL-1) can be successfully detected by the NIR-II LFA, but fail for the colloidal gold LFA. The NIR-II LFA can provide a promising platform for highly sensitive, rapid, and cost-effective method for early diagnosis and mass screening of SARS-CoV-2 infection. Electronic Supplementary Material: Supplementary material (the operation procedure and cost of the materials needed of NIR-II lateral flow assays, the dynamic light scattering spectrum of the NIR-II nanoparticles, the components and testing principle, optimization of main parameters pertaining to the LFA performance, the colloidal gold LFA strip, the fluorescence intensity distribution curves and the T/C values of the strips for clinical samples by NIR-II LFA, and results of clinical swab samples detected by colloidal gold LFA) is available in the online version of this article at 10.1007/s12274-022-4351-1.

A Daytime Multisensor Satellite System for Global Gas Flaring Monitoring

Natural gas flaring (GF) is a longstanding problem for the oil industry. Recent estimates indicate that this phenomenon has increased to levels recorded a full decade earlier. While in 2020 there was a decline in global GF due to COVID-19 pandemic, data suggest that GF continues to be a persistent issue, with solutions remaining difficult or uneconomical in certain countries. Nighttime satellite products are widely used to map and monitor GF affected areas, partially filling the general lack of information from oil companies and/or national reporting. In this work, we assess the potential of daytime infrared satellite observations at high spatial resolution from operational land imager (OLI) and multispectral instrument (MSI) sensors, respectively, onboard Landsat-8 (L8) and Sentinel-2 (S2) satellites, in monitoring GF activity. The normalized hotspot indices (NHI) algorithm is used for this purpose, testing its performance over six different GF sites. Results show the NHI capability in providing accurate information about GF-related thermal (e.g., 100 & x0025;of detections offshore;up to 92 & x0025;onshore), despite some limitations due to clouds and smoke. They open challenging scenarios regarding the possibility of quantifying the volume of emitted gas from daytime S2-MSI and L8-OLI data, integrating information from well-established nighttime operational systems.

Error grid analysis evaluation of noninvasive blood glucose monitoring system of diabetic Covid-19 patients

Due to the life-threatening dangers of diabetic disease and the rapid spread of the Corona pandemic, the demand for continuous glucose monitoring systems increases, especially that complemented with telemedicine technologies. During and after the corona pandemic, the number of diabetes patients is anticipated to rise rapidly. This study aims to learn the interaction between diabetes and COVID-19 and the health complication, owing to control blood glucose levels to decrease these complications. Careful blood sugar control is essential because the poorer health results are strongly linked with greater blood sugar levels in COVID-19 infection patients. The non-invasive glucose detection system is vital to control diabetic COVID-19 patients' health cases. The non-invasive blood glucose monitoring system is based on acousto-optic Raman-Nath interaction using 2MHz ultrasound and 980nm IR laser. Clark's Error Chart and Parkes Error Grid are used for evaluating the non-invasive blood glucose monitoring system and show a promising evaluation result.

Prospects of NIR fluorescent nanosensors for green detection of SARS-CoV-2.

The pandemic of the novel coronavirus disease 2019 (COVID-19) is continuously causing hazards for the world. Effective detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can relieve the impact, but various toxic chemicals are also released into the environment. Fluorescence sensors offer a facile analytical strategy. During fluorescence sensing, biological samples such as tissues and body fluids have autofluorescence, giving false-positive/negative results because of the interferences. Fluorescence near-infrared (NIR) nanosensors can be designed from low-toxic materials with insignificant background signals. Although this research is still in its infancy, further developments in this field have the potential for sustainable detection of SARS-CoV-2. Herein, we summarize the reported NIR fluorescent nanosensors with the potential to detect SARS-CoV-2. The green synthesis of NIR fluorescent nanomaterials, environmentally compatible sensing strategies, and possible methods to reduce the testing frequencies are discussed. Further optimization strategies for developing NIR fluorescent nanosensors to facilitate greener diagnostics of SARS-CoV-2 for pandemic control are proposed.

3D-printed graphene polylactic acid devices resistant to SARS-CoV-2: Sunlight-mediated sterilization of additive manufactured objects.

Additive manufacturing has played a crucial role in the COVID-19 global emergency allowing for rapid production of medical devices, indispensable tools for hospitals, or personal protection equipment. However, medical devices, especially in nosocomial environments, represent high touch surfaces prone to viral infection and currently used filaments for 3D printing can't inhibit transmission of virus [1]. Graphene-family materials are capable of reinforcing mechanical, optical and thermal properties of 3D printed constructs. In particular, graphene can adsorb near-infrared light with high efficiency. Here we demonstrate that the addition of graphene nanoplatelets to PLA filaments (PLA-G) allows the creation of 3D-printed devices that can be sterilized by near-infrared light exposure at power density analog to sunlight. This method has been used to kill SARS-CoV-2 viral particles on the surface of 3D printed PLA-G by 3 min of exposure. 3D-printed PLA-G is highly biocompatible and can represent the ideal material for the production of sterilizable personal protective equipment and daily life objects intended for multiple users.

Whole-organ transdermal photobiomodulation (PBM) of COVID-19: A 50-patient case study.

A nonrandomized 50-person case study of COVID-19-positive patients was conducted employing (for the first time) a regimen of whole-organ deep-tissue transdermal dynamic photobiomodulation (PBM) as a primary (or exclusive) therapeutic modality in the treatment of coronavirus. Therapy sessions comprised algorithmically alternating red (650 nm) and near-infrared (NIR; 850 nm) LEDs with an average irradiance of 11 mW/cm2 dynamically sequenced at multiple pulse frequencies. Delivered via 3D bendable polymeric pads maintaining orthogonal optical incidence to body contours over 1,000 cm2 , a single 84-minute session concurrently delivered 20 kJ to the sinuses and 15 kJ to each lung at skin temperatures below 42°C. Therapeutic outcomes observed include significant reductions in the duration and severity of disease symptoms. Acute conditions including fever, body aches (BA) and respiratory distress comprising paroxysmal coughing; lung congestion, dyspnea and hypoxia; sinus congestion; acute eye inflammation; and extreme malaise were eliminated in 41/50 patients within 4 days of commencing PBM treatments with 50/50 patients fully recovering within 3 weeks with no supplemental oxygen requirements. SpO2 concentrations improved as much as 9 points (average 2.5 points) across the entire study population. The PBM sessions required to completely resolve COVID-19 conditions appears monotonically correlated to the time-to-treatment (TTTx)-the delay between the onset of a patient's symptoms and commencing PBM therapy. In contrast, acute inflammatory symptoms were resolved within 4 days irrespective of TTTx.

A novel design proposal for low-cost vein-viewer for medical and non-contact biometric applications using NIR imaging.

The vein-viewer is a new revolution in the health industry. In fact, it is one of the must-have gadgets for any medical professional. The vein-viewer is device that helps to access easily veins when trying to collect a blood sample or for administering Intravenous (IV) cannulation. It is also an aid for dermatologist/aesthetic physician to access client's veins for sclerotherapy procedures or avoiding veins in cosmetic procedures. The vein-viewer is highly applicable where vascular positioning is really difficult; examples while canulating infants, obese, hairy/dark skins, dialysis/cancer patients etc. In addition, frequent attempts affect patients, causing trauma and subcutaneous haemorrhage. As palm/finger vein patterns are unique and complex, difficult to duplicate or steal as it is beneath the skin. So, in this Covid19 pandemic time, the vein-viewer finds applications in the secure non-contact bio-metric authentications for secure banking and attendance registering system to identify an individual. In this article I am trying to explain the design overview of vein-viewer system, its design challenges, cost aspects, its availability and also sharing a few inputs for the new compact, low-cost design and implementation.

Near-Infrared Light Brightens Bacterial Disinfection: Recent Progress and Perspectives.

Bacterial infection is a universal threat to public health, which not only causes many serious diseases but also exacerbates the condition of the patients of cancer, pandemic diseases, e.g., COVID-19, and so on. Antibiotic therapy has been used to be an effective way for common bacterial disinfection. However, due to the misuse and abuse of antibiotics, more and more antibiotic-resistant bacteria have emerged as fatal threats to human beings. At present, more than 700,000 patients die every year with bacterial infections because of the lack of effective treatment. It is frustrating that the pace of development of antibiotics lags far behind that of bacterial resistance, with an estimation of 10 million deaths per year from bacterial infections after 2050. Facing such a rigorous challenge, approaches for bacterial disinfection are urgently demanded. The recently developed near-infrared (NIR) light-irradiation-based bacterial disinfection is highly promising to shatter bacterial resistance by employing NIR light-responsive materials as mediums to generate antibacterial factors such as heat, reactive oxygen species (ROS), and so on. This treatment approach is proved to be a potent candidate to accurately realize spatiotemporal control, while effectively eradicating multidrug-resistant bacteria and inhibiting antibiotic resistance. Herein, we summarize the latest progress of NIR light-based bacterial disinfection. Ultimately, current challenges and perspectives in this field are discussed.

A two-tiered system of analysis to tackle rice fraud: The Indian Basmati study.

Demand for high quality Basmati rice has increased significantly in the last decade. This commodity is highly vulnerable to fraud, especially in the post COVID-19 era. A unique two-tiered analytical system comprised of rapid on-site screening of samples using handheld portable Near-infrared NIR and laboratory confirmatory technique using a Head space gas chromatography mass spectrometry (HS-GC-MS) strategy for untargeted analysis was developed. Chemometric models built using NIR data correctly predicted nearly 100% of Pusa 1121 and Taraori, two high value types of Basmati, from potential adulterants. Furthermore, rice VOC profile fingerprints showed very good classification (R2 >0.9, Q2 > 0.9, Accuracy > 0.99) for these high quality Basmati varieties from potential adulterant varieties with aldehydes identified as key VOC marker compounds. Using a two-tiered system of a rapid method for on-site screening of many samples alongside a laboratory-based confirmatory method can classify Basmati rice varieties, protecting the supply chain from fraud.