A simple displacement aptamer assay on resistive pulse sensor for small molecule detection

A universal aptamer-based sensing strategy is proposed using DNA modified nanocarriers and Resistive Pulse Sensing (RPS) for the rapid (≤20 min) label free detection of small molecules. The surface a magnetic nanocarrier was first with ssDNA (anchor) which designed to be partially complimentary in sequence aptamer. aptamer anchor form stable dsDNA complex on surface. Upon addition target molecule, conformational change takes place where preferentially binds over anchor; causing released into solution. RPS measures velocity as its changes from ssDNA, used proxy concentration target. length ability extract preconcentrate magnet, shown affect sensitivity. We illustrate versatility assay same Aptamers antibiotic Moxifloxacin, chemotherapeutics Imatinib Irinotecan. In addition, can easily extended detect multiple analytes simultaneously, by utilizing different diameters. Each sized particle functionalised but unique this simultaneous Moxifloxacin. could adapted range targets unlike previous strategies that use nanocarriers, signal not dependent upon tertiary structure aptamer-target interaction.