101. Origami-enabled signal amplification for paper-based colorimetric biosensors
- Author
-
Alejandra Alba-Patiño, Roberto de la Rica, and Steven M. Russell
- Subjects
Detection limit ,Materials science ,business.industry ,010401 analytical chemistry ,Microfluidics ,Metals and Alloys ,02 engineering and technology ,Paper based ,Optical density ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Reagent ,Materials Chemistry ,Optoelectronics ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Instrumentation ,Biosensor ,Signal amplification - Abstract
Signal amplification in colorimetric biosensors usually requires labile reagents and/or additional steps, which are not ideal for in-field measurements. Here we show that the limit of detection of a gold nanoparticle-labeled colorimetric immunosensor can be decreased 10-fold by performing the assay on a folded piece of paper. In this approach, the intrinsic porosity of the substrate enables generating multiple signals with a single drop of reagent. This yields combined signals with higher optical density thanks to the semitransparent nature of the wet material. It will be shown that this method can decrease the limit of detection 10 times in a model immunosensor for the detection of immunoglobulins. The procedure is so straightforward that it could be easily implemented to decrease the limit of detection of microfluidic paper-based analytical devices with colorimetric readouts.
- Published
- 2018