Miniaturized sensor for electroanalytical and electrochemiluminescent detection of pathogens enabled through laser-induced graphene electrodes embedded in microfluidic channels.

High performance, laser-induced graphene (LIG) electrodes were integrated into adhesive tape-based microfluidic channels to realize both electrochemical (EC) and electrochemiluminescent (ECL) detection approaches. This provides strategies for low limits of detection, simple hardware requirements and inexpensive fabrication, which are characteristics required for assays in the competitive point-of-care (POC) sensor field. Here, electrode design and microchannel dimensions were studied and a DNA hybridization assay with liposomes for signal amplification was developed for the specific detection of DNA derived from as the model analyte.

Silver-doped hydroxyapatite for formaldehyde determination by digital-image colorimetry.

Silver-hydroxyapatite material (Ag-HAP) was first proposed as material for trace-level formaldehyde detection based on Tollens' reaction on the material surface. By using this Ag-HAP material, the chemical reduction caused by formaldehyde occurred directly on the solid surface. The material color changed from off-white to the yellow or brown of silver nanoparticles depending on the formaldehyde concentration.