Current signal amplification strategies in aptamer-based electrochemical biosensor: A review

Due to their high specificity and affinity towards various targets, along with other unique advantages such as stability and low cost, aptamers are widely applied in analytical techniques. A typical aptamer-based electrochemical biosensor is composed of a aptamer as the biological recognition element and transducer converting the biologic interaction into electrical signals for the quantitative measurement of targets. Improvement of the sensitivity of a biosensor is significantly important in order to achieve the detection of biomolecules with low abundance, and different amplification strategies have been explored. The strategies either employ nanomaterials such as gold nanoparticles to construct electrodes which can transfer the biological reactions more efficiently, or attempt to obtain enhanced signal through multi-labeled carriers or utilize enzyme mimics to catalyze redox cycling. This review discusses recent advances in signal amplification methods and their applications. Critical assessment of each method is also considered.