A paper based microfluidic device for the detection of arsenic using a gold nanosensor

Abstract

A paper based microfluidic device is fabricated that can rapidly detect very low concentrations of As³⁺ ions using a gold nanosensor, Au–TA–TG. This simple but efficient system develops a visible bluish-black colour precipitate due to the formation of nanoparticle aggregates through transverse diffusive mixing of Au–TA–TG with As³⁺ ions on a paper substrate. The approach is extremely selective for arsenic with a detection limit of 1.0 ppb, which is lower than the WHO's reference standard for drinking water.