Disposable solar microcell array-based addressable photoelectrochemical sensor for high-throughput and multiplexed analysis of salivary metabolites
Min Liu, Danting He, Zhihong Liu, Chengguo Hu
Abstract
The high-throughput detection of multiple metabolites in saliva by electrochemical sensors is usually a challenge, which however is essential to the comprehensive evaluation of health status or screening of diseases. Here, a light-addressable and paper-based hydrogen peroxide (H 2 O 2 ) photoelectrochemical (PEC) sensor for the high-throughput detection of multiple salivary metabolites is reported. This sensor has a unique solar microcell array structure with a silver nanowires/fullerene-Congo red (AgNWs/C 60 -CR) disc working electrode (WE) and a single-walled carbon nanotubes/platinum nanowires (SWCNTs/PtNWs) ring reference/counter electrode (RE/CE) in each microcell. Enzymes of different metabolites are immobilized on different separated microcells of a cover slide over the sensor, from which enzymatically produced H 2 O 2 can react with p-hydroxyphenyl boric acid (4-HPBA) on the WE of the sensor to generate hydroquinone (HQ) for photocurrent responses. Based on this strategy, a disposable PEC sensor of saliva was developed, which allows the multiplexed detection of uric acid (UA), glucose (GLU) and lactate (LA) in diluted human saliva with high sensitivity and selectivity . Moreover, the detection throughput and application field of the sensor can be easily extended by connecting a series of sensors in parallel or varying the enzymes. The present work thus establishes a cost-effective approach to the scalable construction of versatile biosensing platforms with tunable throughput and varied analytes.