Development of 1,1′-oxalyldiimidazole chemiluminescent biosensor using the combination of graphene oxide and hairpin aptamer and its application

Highly sensitive biosensor with 1,1'-oxalyldiimidazole chemiluminescence (ODI-CL) detection was developed to rapidly quantify Vibrio (V) parahaemolyticus without time-consuming procedures such as multiple long-incubations and washings. When V. parahaemolyticus in Tris-HCl (pH 7) and hairpin DNA aptamer conjugated with TEX615 in DNA free deionized water were consecutively added in PBS buffer (pH 7.4) containing graphene oxides (GOs), V parahaemolyticus and GOs bind competitively to hairpin DNA aptamer conjugated with TEX615 during 10 min of incubation at room temperature. Brightness of light immediately emitted with the addition of ODI-CL reagents (e.g., ODI, H2O2) after the incubation was dependent on the concentration of V. parahaemolyticus in a sample. The dynamic range of linear calibration curve for the quantification of V. parahaemolyticus in a sample was from 4375 to 70,000 cells/ml. The limit of detection (LOD=bacicground+3 x standard deviation, 2230 cells/ml) of the biosensor operated with good accuracy, precision, and recovery was lower than those of conventional assay methods such as time-consuming and expensive enzyme-linked immunosorbent assays. (C) 2013 Elsevier B.V. All rights reserved.