A reduced graphene oxide-titanium dioxide nanocomposite based electrochemical aptasensor for rapid and sensitive detection of Salmonella enterica
Document Type
Article
Publication Date
1-1-2019
Abstract
Recent foodborne outbreaks in multiple locations necessitate the continuous development of highly sensitive and specific biosensors that offer rapid detection of foodborne biological hazards. This work focuses on the development of a reduced graphene oxide‑titanium dioxide (rGO-TiO 2 ) nanocomposite based aptasensor to detect Salmonella enterica serovar Typhimurium. A label-free aptamer was immobilized on a rGO-TiO 2 nanocomposite matrix through electrostatic interactions. The changes in electrical conductivity on the electrode surface were evaluated using electroanalytical methods. DNA aptamer adsorbed on the rGO-TiO 2 surface bound to the bacterial cells at the electrode interface causing a physical barrier inhibiting the electron transfer. This interaction decreased the DPV signal of the electrode proportional to decreasing concentrations of the bacterial cells. The optimized aptasensor exhibited high sensitivity with a wide detection range (10 8 to 10 1 cfu mL −1 ), a low detection limit of 10 1 cfu mL −1 and good selectivity for Salmonella bacteria. This rGO-TiO 2 aptasensor is an excellent biosensing platform that offers a reliable, rapid and sensitive alternative for foodborne pathogen detection. © 2019
Keywords
Reduced graphene oxide, Titanium dioxide, Electrochemical aptasensor, S. Typhimurium
Divisions
fac_eng,fac_med,InstituteofBiologicalSciences,nanotechnology
Funders
Ministry of Higher Education (MOHE) Transdisciplinary Research Grant Scheme ( TR002B-2014B and TR002C-2014B ),University of Malaya Flagship grants ( FL001A-14AET , FL001B-14AET )
Publication Title
Bioelectrochemistry
Volume
127
Publisher
Elsevier