RESUMO
Sensitive detection of SARS-CoV-2 is of great importance for inhibiting the current pandemic of COVID-19. Here, we report a simple yet efficient platform integrating a portable and low-cost custom-made detector and a novel microwell array biochip for rapid and accurate detection of SARS-CoV-2. The instrument exhibits expedited amplification speed that enables colorimetric read-out within 25 minutes. A polymeric chip with a laser-engraved microwell array was developed to process the reaction between the primers and the respiratory swab RNA extracts, based on reverse transcriptase loop-mediated isothermal amplification (RT-LAMP). To achieve clinically acceptable performance, we synthesized a group of six primers to identify the conserved regions of the ORF1ab gene of SARS-CoV-2. Clinical trials were conducted with 87 PCR-positive and 43 PCR-negative patient samples. The platform demonstrated both high sensitivity (95.40%) and high specificity (95.35%), showing potentials for rapid and user-friendly diagnosis of COVID-19 among many other infectious pathogens.
RESUMO
Urolithiasis is a common disease that affects 5% to 8.8% of the world population with high recurring frequency. Therefore, there is an urgent need for the rapid and efficient diagnostics of urolithiasis. In this study, we developed a quantum dots (QDs)-based sensor for detecting urolithiasis oxalate. Urolithiasis oxalate was quantified by reducing Cu2+ to Cu+, which can be selectively recognized by CdTe QDs. The homogeneous sensing system shows high sensitivity for oxalate detection in the range of 0.1 µM to 10 mM within 6 min; moreover, the visual detection of 10 µM oxalate could be achieved by the naked eye. Our method was tested on 53 clinical samples; it showed 100% specificity and sensitivity for calcium oxalate urolithiasis compared with clinical diagnosis, even for hematuria samples. Furthermore, this method can be expanded to other wide range of biochemistry applications for medical diagnosis and point-of-care testing.