Cost‐Effective and Robust Multispectral Light‐Emitting Diode Device for the Readout of Plasmonic Microarray Sensors

Abstract

Localized surface plasmon resonance (LSPR) is a phenomenon known for more than 100 years, which arises from the interaction of light with metallic nanoparticles. In recent years, the field of LSPR sensing has become increasingly important in bioanalytics. Herein, a simple and robust device setup to perform time‐resolved LSPR measurements with inexpensive array sensor chips is presented. For this purpose, gold nanoparticles are spotted onto glass substrates under different conditions (droplet size/number, temperature, and humidity) to achieve an optimal signal‐to‐noise ratio. To verify the setup and the spotted sensor chips, bulk sensitivity measurements with solutions of varying refractive index and surface sensitivity measurements with layer‐by‐layer (LbL) deposition are performed. It is shown that slower drying minimizes the edge effects of ring‐like deposits (coffee ring effect) and that the spots with higher particle densities are more suitable for sensor applications. In general, the use of six light‐emitting diode (LEDs) enables a simple centroid calculation as well as an evaluation via individual LED intensities. The presented cost‐effective system allows parallel reading of more than 100 spots in a label‐free platform, and together with the optimized low‐cost sensors, it provides an interesting alternative for the development of future on‐site diagnostics.

LSPR‐Based Biosensing Enables the Detection of Antimicrobial Resistance Genes

“…Here we used a custom-built LSPR device for the detection of an antimicrobial resistance gene, blaSHV. To the best of our knowledge, this was the first report of an LSPR-based method with a low-cost and easy-to-fabricate sensor, even in microarray scale, [23,54] of immobilized spherical AuNPs that can detect SNPs in flow-through measurements and also enables the analysis of binding kinetic parameters. Varying the analyte sequence length revealed that shorter sequences result in larger LSPR shifts, as well as faster association rates as compared to longer sequences.…”

“…In addition, sensors used for these measurements are usually based on lithographically fabricated chips. [ 52 ] To the best of our knowledge, this is the first report of an LSPR‐based method with a low‐cost and easy‐to‐fabricate sensor, even in microarray scale, [ 23,54 ] of immobilized chemically synthesized spherical gold NPs that can meet all above‐stated requirements.…”