Nanochannel confined graphene quantum dots/platinum nanoparticles boosts electrochemiluminescence of luminal-O2 system for sensitive immunoassay

Yucheng Zhou; Chaoyan Zhang; Jiyang Liu; Yiping Mou

doi:10.1016/j.talanta.2024.127223

Nanochannel confined graphene quantum dots/platinum nanoparticles boosts electrochemiluminescence of luminal-O₂ system for sensitive immunoassay

Talanta. 2024 Nov 20:285:127223. doi: 10.1016/j.talanta.2024.127223. Online ahead of print.

Authors

Yucheng Zhou¹, Chaoyan Zhang², Jiyang Liu³, Yiping Mou⁴

Affiliations

¹ General Surgery, Cancer Center, Department of Gastrointestinal and Pancreatic Surgery, Zhejiang Provincial People's Hospital, Hangzhou Medical College, Hangzhou 310014, China.
² School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China.
³ School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China. Electronic address: liujy@zstu.edu.cn.
⁴ General Surgery, Cancer Center, Department of Gastrointestinal and Pancreatic Surgery, Zhejiang Provincial People's Hospital, Hangzhou Medical College, Hangzhou 310014, China. Electronic address: mouyiping@hmc.edu.cn.

PMID: 39613487
DOI: 10.1016/j.talanta.2024.127223

Abstract

Sensitive detection of tumor biomarkers is of great significance for early cancer diagnosis, treatment evaluation, and recurrence monitoring. Development of convenient electrochemiluminescence (ECL) immunosensor using dissolved oxygen (O₂) as an endogenous co-reactant of luminol combined with efficient nanocatalysts to boost ECL signal in neutral media is highly desirable. Herein, sensitive detection of tumor biomarker using ECL of luminal-O₂ enhanced by confinement of nitrogen-doped graphene quantum dots (N-GQDs) and platinum nanoparticles (PtNPs) on nanochannel array was demonstrated. A high-density nanochannel array-modified electrode was achieved by rapidly growing an amino-functionalized. Vertically-ordered mesoporous silica film (NH₂-VMSF) on the inexpensive and readily available indium tin oxide (ITO) electrode. Through simple electrodeposition, N-GQDs were confined and PtNPs were in-situ synthesized in nanochannels of NH₂-VMSF. These confined nanocomposites catalyzed the electroreduction of O₂ at negative potentials to generate a large amount of reactive oxygen species (ROS) and facilitated luminol oxidation, enhancing the ECL signal of luminol by 25 times. Two immunosensors were fabricated after covalent immobilization of the recognition antibody of carbohydrate antigen 199 (CA199) or carbohydrate antigen 125 (CA125) on the outer surface of the NH₂-VMSF and blocking of non-specific sites. When tumor biomarkers bind to the corresponding antibodies on the recognition interface, the formed immunocomplex hindered the diffusion of luminol to the underlying electrode, resulting in a decrease in the ECL signal and sensitive detection of tumor biomarker. The constructed CA199 immunosensor exhibited a linear detection range for CA199 from 0.5 mU mL^-1 to 50 U mL^-1, with a detection limit (DL) of 0.03 mU mL^-1. For CA125 detection, linear detection ranged from 0.5 mU mL^-1 to 500 U mL^-1, with a DL of 0.005 mU mL^-1. The fabricated immunosensors demonstrated good selectivity and high reproducibility. This study provides great potential for the development of efficient luminol ECL systems in neutral media and expands the biological application in sensitive detection of tumor biomarker.

Keywords: Confined nanocatalyst; Dissolved oxygen; Electrochemiluminescence immunosensor; Luminol; Tumor biomarker.