Fabrication and study of microfluidic devices for toxic metal ions detection

Abstract

Microfluidic device is mainly used in Lab-on-Chip (LOC) which plays a vital role in chemical and biological analysis. Micromixer is an important building block in LOC. The fluid flow in microchannels is laminar and hence mixing of fluids may not happen easily. Various techniques are being used to make mixing more efficient. The main requirement of a micromixer is to achieve complete mixing with low flow rate, minimum channel length and minimum pressure drop. This work focuses on the effect of modifying the structure of the microfluidic channel to improve the mixing efficiency. The mixing performances of serpentine channel with and without grooves are compared with straight channel for various flow rates such as 1, 10, 25, 50, 75 and 100 and#956;L/min. The research work is intended to study the microfluidic device for the detection of Mercury ions in water. Mercury (Hg2+) ion is one of the heavy metal ions present in water and highly poisonous to human. Thus, developing an efficient sensor at low cost for the detection of mercury ions in water is essential. Here, the development of a fluorometric sensor using the microfluidic device with high sensitivity and selective detection of Hg2+ in water is discussed. Very tiny quantity of sensing fluids (~2.8 and#1049117;L) comprising L-Arginine capped gold nanoparticles functionalized with Rhodamine 6G allowed the on-chip fluorescence detection of Hg2+ ions concentration. The developed microfluidic device senses the presence of Hg2+ ions concentration from 2 to 12 nM through the change in intensity of fluid fluorescence. The sensor response is found to be linear with respect to the Hg2+ ions concentration newline