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Ultrasensitive Detection of Biomarkers by Using a Molecular Imprinting Based Capacitive Biosensor
Published on: February 16, 2018
The self-powered electrochemical biosensing platform with multi-amplification strategy for ultrasensitive detection
Yong-Ping Gao1, Ke-Jing Huang2, Fu-Ting Wang3
1International Joint Research Laboratory of New Energy Materials and Devices of Henan Province, School of Physics and Electronics, Henan University, Kaifeng, 475004, PR China; School of Science and Engineering, Xinyang University, Xinyang, 464000, PR China.
Abstract:
A self-powered biosensor (SPB) was constructed for the ultra-sensitive detection of microRNA-155 (miR-155) by combining a capacitor/enzymatic biofuel cell (EBFC), a strategy of rolling circle amplification (RCA) and a digital multimeter (DMM). The experimental results show that the sensitivity of the assembled EBFC-SPB can reach 15.85 μA/pM with the action of matching capacitor, which is 513% of that without capacitor (3.09 μA/pM). This achieves the first signal amplification. Furthermore, when the target miR-155 triggers RCA, electrons are continuous generated and flow to the biocathode through the external circuit to catalyze the reduction of oxygen and release [Ru(NH3)6]3+ electron acceptor. This achieves the second signal amplification. Finally, DMM is used to convert the signal into instantaneous current and amplify it for real-time reading. This achieves the third signal amplification. Therefore, the limit of detection (LOD) of the developed biosensor is as low as 0.17 fM (S/N = 3), and the linear range is between 0.5 fM and 10,000 fM, indicating that the EBFC-SPB has a broad application prospect for cancer marker of miR-155 with ultrasensitive detection.
