Carbon Dot-Modified Branched TiO2 Photoelectrochemical Glucose Sensors with Visible Light Response

Run Yuan; Bingdong Yan; Caiyan Lai; Xiaohong Wang; Yang Cao; Jinchun Tu; Yi Li; Qiang Wu

doi:10.1021/acsomega.3c02202

Carbon Dot-Modified Branched TiO₂ Photoelectrochemical Glucose Sensors with Visible Light Response

ACS Omega. 2023 Jun 5;8(24):22099-22107. doi: 10.1021/acsomega.3c02202. eCollection 2023 Jun 20.

Authors

Run Yuan¹, Bingdong Yan¹, Caiyan Lai¹, Xiaohong Wang¹, Yang Cao¹, Jinchun Tu¹, Yi Li¹, Qiang Wu²

Affiliations

¹ State Key Laboratory of Marine Resource Utilization in South China Sea, School of Materials Science and Engineering, Hainan University, Haikou 570228, P. R. China.
² The Second Affiliated Hospital, School of Tropical Medicine, Key Laboratory of Emergency and Trauma of Ministry of Education, Research Unit of Island Emergency Medicine, Chinese Academy of Medical Sciences (No. 2019RU013), Hainan Medical University, Haikou 571199, P. R. China.

Abstract

The development of a photoelectrochemical (PEC) sensor for the sensitive and rapid detection of glucose is highly desirable. In PEC enzyme sensors, inhibition of the charge recombination of electrode materials is an efficient technique, and detection in visible light can prevent enzyme inactivation due to ultraviolet irradiation. In this study, a visible light-driven PEC enzyme biosensor was proposed, using CDs/branched TiO₂ (B-TiO₂) as the photoactive material and glucose oxidase (GOx) as the identification element. The CDs/B-TiO₂ composites were produced via a facile hydrothermal method. Carbon dots (CDs) can not only act as photosensitizers but also inhibit photogenerated electron and hole recombination of B-TiO₂. Under visible light, electrons in the carbon dots flowed to B-TiO₂ and further to the counter electrode through the external circuit. In the presence of glucose and dissolved oxygen, H₂O₂ generated through the catalysis of GOx could consume electrons in B-TiO₂, causing a decrease in photocurrent intensity. Ascorbic acid was added to ensure the stability of the CDs during the test. Based on the variation of the photocurrent response, the CDs/B-TiO₂/GOx biosensor presented a good sensing performance of glucose in visible light, its detection range was from 0 to 9.00 mM, and the detection limit was 0.0430 mM.