An Inexpensive and Effective Aptamer‐Based Evanescent Wave Biosensor

Abstract

We have developed an inexpensive and effective evanescent wave biosensor utilizing 3D printed scaffolding and readily available electronics. This biosensor consists of a 3D printed brace, an inexpensive LED light source and cylindrical lens to direct the light in an elliptical pattern, and an acrylic slide on which DNA is immobilized. This scaffold allows light to enter the slide at above the critical angle for total internal reflectance, ensuring that the immobilized DNA experiences excitation by an evanescent wave. If the immobilized DNA is an aptamer‐based biosensor with a fluorescent reporter tag, binding of target that is washed across the slide surface will result in characteristic and measurable fluorescence changes. The utility of this inexpensive DIY setup was evaluated with image‐analysis software to create dose‐response curves for the response of both a botulinum toxin serotype A‐binding aptamer biosensor and a uranium ion‐binding aptamer biosensor, and demonstrates the potential utility of these convenient evanescent wave biosensors.Support or Funding InformationSupport for this work comes from the Metropolitan State University of Denver Provost's and LAS Dean's offices.