The Challenges and Solutions in Developing Ultrasensitive Biosensors.
Wu Y, Tilley RD and Gooding JJ
J Am Chem Soc. 2018. Nov 21
This Perspective focuses on the latest strategies and challenges for the development of bioanalytical sensors with sub-picomolar detection limits. Achieving sub-picomolar detection limits has three major challenges. These are 1) assay sensitivity, 2) response time and 3) selectivity (including limiting background signals). Each of these challenges, and how nanomaterials provide the solutions, is dis-cussed. Strategies to gain greater sensitivity include confining the sensing volume to the nanoscale, as used in nanopore or nanoparticles based sensors, while nanoparticles are ubiquitous in amplification. Methods to improve response time typically focus on obtaining an intimate mixture between the sen-sor and the sample either by extending the length scale of nanoscale sensors using nanostructuring or by dispersing magnetic nanoparticles through the sample to capture the analyte. Nanoparticles loaded with many biorecognition species are one solution to help address the challenge of selectivity. Many of the examples in the perspective explore the detection of prostate specific antigen (PSA) to enable a comparison between strategies. Finally the exciting future opportunities in developing single molecules sensors and the requirement to go even lower in concentration are explored.