Selective oxidation of p-phenylenediamine for blood glucose detection enabled by Se-vacancy-rich TiSe2-x@Au nanozyme

Authors：Sun, Caixia; Zhang, Xue; Huang, Hao^*; Liu, Ya; Mo, Xianwei; Feng, Yufei; Wang, Jiahong; Zhou, Wenhua; Chu, Paul K.; Yu, Xue-Feng; Liu, Wenxin^*

Source：Biosensors and Bioelectronics, 2023, 241: 115665.

DOI：10.1016/j.bios.2023.115665

• Transition metal dichalcogenides
• Se vacancies
• Nanozymes
• Selective oxidation
• Glucose detection

Nanozymes with enzyme-like characteristics have drawn wide interest but the catalytic activity and substrate selectivity of nanozymes still need improvement. Herein, Se-vacancy-rich TiSe2-x@Au nanocomposites are designed and demonstrated as nanozymes. The TiSe2-x@Au nanocomposites show excellent peroxidase-like activity and the chromogenic substrate p-phenylenediamine (PPD) can be selectively oxidized to compounds that exhibit an absorption peak at 413 nm that differs from that of self-oxidation or generally oxidized species, suggesting high catalytic activity and strong substrate selectivity. Theoretical calculations reveal that the PPD adsorption geometry at Se vacancies with an adsorption energy of -3.00 eV shows a unique spatial configuration and charge distribution, thereby inhibiting the free reaction and promoting both the activity and selectivity in PPD oxidation. The TiSe2-x@Au colorimetric system exhibits a wide linear range of 0.015 mM-0.6 mM and a low detection limit of 0.0037 mM in the detection of glucose. The blood glucose detection performance for human serum samples is comparable to that of a commercial glucose meter in the hospital (relative standard deviation < 6%). Our findings demonstrate a new strategy for rapid and accurate detection of blood glucose and our results provide insights into the future design of nanozymes.

• Institution
  中国科学院; 广东医学院; 1