Electrochemical aptamer sensor for small molecule assays.

Detection and quantification of small molecules have played essential roles in environmental analysis and clinical diagnosis. Aptamers are oligonucleic acids that bind to a specific target molecule with high specificity and affinity which are promising features for sensing small molecules. Electrochemical detection is an attractive way to exploit aptamer sensors (aptasensors) because of its high sensitivity, simple instrumentation, low cost, fast response and portability. Herein, we describe a label-free small molecular aptasensor based on a signal-amplification mechanism which uses gold nanoparticles. This aptasensor can selectively detect low nanomolar levels of ATP, the example target compound.