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.

Exploration of nitrogen-doped grape peels carbon dots for baicalin detection

Baicalin, a flavonoid compound extracted from the rhizome of Scutellar iae Baicalensis, plays a vital role in improving liver function after injury, reducing liver disease and treating primary liver cancer, which is also the first SARS-CoV-2 3CLpro virus inhibitor according to the latest research data published in Bio-Rxiv. Therefore, constructing a simple and highly sensitive analytical method for the determination of baicalin is of great significance for the clinical and pharmacy settings. Herein, for the first time, carbon dots are explored for baicalin detection. Using biomass waste grape peels as the organic carbon source, nitrogen-doped fluorescent carbon dots (PT-NCDs) were fabricated, which were synthesized perfectly by a simple, environmentally friendly and one-step solid-phase thermal method without adding any other organic or acid/base reagents. Based on the synergistic effect of photo-induced electron transfer and dynamic quenching, a quenched fluorescence sensor for the determination of baicalin with a good linear range of 0.1-20 mu M and a satisfactory detection limit of 43.8 nM was constructed, which successfully quantified trace amount of baicalin in baicalin capsules, human serum and urine samples. The results indicate that PT-CDs are expected to become potential sensing materials for the real-time monitoring of baicalin in organisms, which is very important for our health. (C) 2021 Elsevier Ltd. All rights reserved.