Electrochemiluminescence detection of Escherichia coli O157:H7 based on mesoporous Ca-doped MgAl2O3–G–SiO2 biosensor

Abstract

This paper describes the development of a graphene-based mesoporous electrochemical biosensor for the quantitative detection of Escherichia coli (E. coli) O157:H7 based on biocompatible mesoporous Ca-doped MgAl₂O₃–G–SiO₂ (CMAGS) nanomaterials. The nanocomposites were morphologically characterized using various techniques, such as XRD, SEM, BET, HRTEM, Raman, DRS, and XPS. In addition, the active materials for the sensing test were electrochemically characterized using cyclic voltammetry (CV). The uniform film for E. coli O157:H7 was successfully established through a self-assembly route. The target bacteria were directly sensed by the electrode, thus allowing E. coli O157:H7 to be selectively recognized; E. coli O157:H7 was detected using the cyclic voltammetry sensing system. Under optimal conditions, the linear relationships between E. coli O157:H7 concentrations were obtained from 10¹ CFU to 10¹⁰ CFU with a 10¹ CFU limit of detection (LOD). The biosensor was also successfully used in the detection of water samples. A mesoporous Ca-doped MgAl₂O₃–G–SiO₂ (CMAGS)-based sensing method for E. coli O157:H7 was reported for the first time. The sensing system showed high selectivity to the target analyte and is expected to lead to new opportunities, such as speeding up disease diagnosis, treatment, and prevention with pathogens.