A paper-based microfluidic sensor array combining molecular imprinting technology and carbon quantum dots for the discrimination of nitrophenol isomers

• Published in: Journal of hazardous materials 2022-08, Vol.435, p.129012-129012, Article 129012
• Main Authors: Zhu, Liang, Mei, Xuecui, Peng, Zhengchun, Yang, Jiao, Li, Yingchun
• Format: Article
• Language: English
• Subjects: Carbon - chemistry; Carbon quantum dots; Limit of Detection; Microfluidics; MIPs; Molecular Imprinting; Nitrophenol isomers; Nitrophenols; Quantum Dots; Sensor array; Spectrometry, Fluorescence; μPADs
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2022.129012

Paper-based microfluidic analytical devices (μPADs) have recently attracted attention as a rapid test kit owing to their low cost and nonrequirement for external driving pump. However, low accuracy and poor anti-interference ability of μPADs under complex detection condition limit their practical applications. Here, we present a facile way to prepare a novel fluorescence sensor-array μPAD for multi-analyte discrimination based on molecular imprinting technology, and its sensing behavior was studied by using three nitrophenol (NP) isomers (2-, 3-, and 4-NP) as the testing models. Carbon quantum dots (CQDs) emitting blue light were grafted on glass-fiber paper, followed by in-situ modification of three types of molecularly imprinted polymers (MIPs) with 2-, 3-, and 4-NP as template. Each sensing unit on the array showed differential yet cross-reactive binding affinity to NP isomers, resulting in distinct fluorescence quenching efficiency. Thus, precise distinguishment of the three NPs was realized with the MIPs/CQDs/paper-based sensor array. Furthermore, the discrimination ability of the platform was evaluated in mixtures of the NP isomers. Practicability of this apparatus was validated by identification of blind samples and 100% accuracy was achieved. The μPAD has proven to be highly sensitive and accurate, which will serve as an ideal analytical tool in the fields of environment monitoring, disease prognosis, food safety and so on. [Display omitted] •Introduction of the sensor array improves accuracy and interference resistance of the μPAD in complex environments.•A portable apparatus was constructed by combining array, MIP and μPAD for multiple analytes detection.•The platform exhibited excellent performance in discrimination and determination of single and mixed NP isomers.•This approach is versatile and can be extended for identification of other analytes by alternating template molecules.