Hand-Held Zoom Micro-Imaging System Based on Microfluidic Chip for Point-of-Care Testing (POCT) of Vaginal Inflammation

An Integrated and Multi-Target Nucleic Acid Isothermal Analysis System for Rapid Diagnosis of Vulvovaginal Candidiasis

Rapid identification of Candida species is significant for the diagnosis of vulvovaginal candidiasis (VVC). An integrated and multi-target system for the rapid, high-specificity, and high-sensitivity detection of four Candida species was developed. The system consists of a rapid sample processing cassette and a rapid nucleic acid analysis device. The cassette could process the Candida species to release nucleic acids in 15 min. The released nucleic acids were analyzed by the device as fast as within 30 min, using the loop-mediated isothermal amplification method. The four Candida species could be simultaneously identified, with each reaction using only 1.41 µL of reaction mixture, which was low cost. The RPT (rapid sample processing and testing) system could detect the four Candida species with high sensitivity (<2 CFU/reaction) and high specificity. The system also processed and analyzed 32 clinical samples, giving the results with high clinical sensitivity and specificity. Hence, the system was a significant and effective platform for the diagnosis of VVC. Furthermore, the period of validity of the reagents and chips used in the system was >90 days, and the system could also be used for the detection of bacteria.

Electrochemical Detection of Ascorbic Acid in Finger-Actuated Microfluidic Chip

The traditional quantitative analysis methods of ascorbic acid (AA), which require expensive equipment, a large amount of samples and professional technicians, are usually complex and time-consuming. A low-cost and high-efficiency AA detection device is reported in this work. It integrates a three-electrode sensor module prepared by screen printing technology, and a microfluidic chip with a finger-actuated micropump peeled from the liquid-crystal display (LCD) 3D printing resin molds. The AA detection process on this device is easy to operate. On-chip detection has been demonstrated to be 2.48 times more sensitive than off-chip detection and requires only a microliter-scale sample volume, which is much smaller than that required in traditional electrochemical methods. Experiments show that the sample and buffer can be fully mixed in the microchannel, which is consistent with the numerical simulation results wherein the mixing efficiency is greater than 90%. Commercially available tablets and beverages are also tested, and the result shows the reliability and accuracy of the device, demonstrating its broad application prospects in the field of point-of-care testing (POCT).