A Membrane-based Disposable Well-Plate for Cyanide Detection Incorporating a Fluorescent Chitosan-CdTe Quantum Dot

• Published in: Analytical Sciences 2020/02/10, Vol.36(2), pp.193-199
• Main Authors: PENGPUMKIAT, Sumate, WU, Yuanyuan, SUMANTAKUL, Saichon, REMCHO, Vincent T.
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Bonding agents; Cadmium Compounds - chemistry; Cadmium tellurides; CdTe quantum dot; Chemical compounds; Chemistry; Chitosan; Chitosan - chemistry; Copper; Copper compounds; Cost analysis; cyanide detection; Cyanides; Cyanides - analysis; Drinking water; Fluorescence; Fluorescent Dyes - chemistry; Fluorophores; Glass; Low cost; Membranes; Microfibers; Nanoparticles; Polycaprolactone; Quantum dots; Quantum Dots - chemistry; Quenching; Reproducibility of Results; Spectrometry, Fluorescence; Tellurium - chemistry; Well-plate
• ISSN: 0910-6340; 1348-2246
• DOI: 10.2116/analsci.19P267

A novel approach to building a membrane-based disposable well-plate, here applied to cyanide detection, is described. Chitosan encapsulated CdTe quantum dots with a maximum emission at 520 nm (CS-QD520) were used as fluorophores. The CS-QD520 nanoparticle was specifically quenched by copper(II), and the quenched CS-QD520 (Cu-CS-QD520) was deposited onto a glass microfiber filter (GF/B). Subsequent introduction of cyanide ion resulted in fluorescence recovery. The “signal-ON” fluorescence linearly correlated to cyanide concentrations in the range of 38.7 to 200 μM with a limit of detection of 11.6 μM. The assay was incorporated into a membrane-based well-plate format to enhance sample throughput. A three-layer paper/glass microfiber well plate design was cut using a laser cutter and assembled using a polycaprolactone (PCL) as a bonding agent in a low-cost laminator. The experimental conditions were optimized and applied to detect cyanide in drinking water with rapid, high-throughput, low-cost analysis.