Design of microfluidic experimental setup for the detection of heavy metal ions using piezoresistive BioMEMS sensor

Abstract

Purpose This paper aims to propose a new microfluidic portable experimental platform for quick detection of heavy metal ions (HMIs) in picomolar range. The experimental setup uses a microfabricated piezoresistive sensor (MPS) array of eight cantilevers with ion-selective self-assembled monolayer's (SAM). Design/methodology/approach Most of the components used in this experimental setup are battery operated and, hence, portable to perform the on-field experiments. HMIs (antigen) and thiol-based SAM (antibody) interaction start bending the microcantilever. This results in a change of resistance, which is directly proportional to the surface stress produced due to the mass of targeted HMIs. The authors have used Cysteamine and 4-Mercaptobenzoic acid as a thiol for creating SAM to test the sensitivity and identify the suitable thiol. Some of the cantilevers are blocked using acetyl chloride to use as a reference for error detection. Findings The portable experimental platform achieves very small detection time of 10-25 min with a lower limit of detection (LOD) 0.762 ng (6.05 pM) for SAM of Cysteamine and 4-Mercaptobenzoic acid to detect Mn2+ ions. This technique has excellent potential and capability to selectively detect Hg2+ ions as low as 2.43 pM/mL using SAM of Homocysteine (Hcys)-Pyridinedicarboxylic acid (PDCA). Research limitations/implications As microcantilever is very thin and fragile, it is challenging to apply a surface coating to have selective detection using Nanadispenser. Some of the cantilevers get broken during this process. Originality/value The excessive use and commercialization of NPs are quickly expanding their toxic impact on health and the environment. Also, LOD is limited to nanomolar range. The proposed method used the combination of thin-film, NPs, and MEMS-based technology to overcome the limitation of NPs-based technique and have picomolar range of HMIs detection.

Highly selective sensor for the detection of Hg 2+ ions using homocysteine functionalised quartz crystal microbalance with cross‐linked pyridinedicarboxylic acid

“…To test our functionalised QCM sensor on a VNA‐based portable experimental platform for microfluidic application to selective detect Hg 2+ ions, we have performed the experiments for checking the sensitivity towards the Hg 2+ ions. We have already investigated selectivity of HCys‐PDCA for selectively detected the Hg 2+ ions using the MEMS‐based piezoresistive experimental platform by Rotake et al [54]. Here, we have focused on the detection of Hg 2+ ions using portable and quick VNA‐based frequency sensing approach.…”

“…So there is a need for the design and development of the portable experimental platform for on‐site mercurydetection. We have already investigated SAM of homocysteine (HCys)‐pyridinedicarboxylic acid (PDCA) for selectively detected the Hg 2+ ions using MEMS‐based piezoresistive experimental platform by Rotake et al [54, 55]. This microcantilever‐based approach is capable of detecting mercury ions at the picomolar range but not suitable for a higher concentration limit provided by WHO.…”

Ultrasensitive detection of cadmium ions using a microcantilever-based piezoresistive sensor for groundwater

“…We have previously investigated SAMs of homocysteine (HCys) and pyridinedicarboxylic acid (PDCA) for the selective sensing of Hg(II) ions using a portable piezoresistive platform [39,40]. Experimental results confirmed that proposed setup is capable of sensing in the picomolar range.…”

Ultrasensitive detection of Cadmium ions using a microcantilever-based piezoresistive sensor for groundwater

“…We have previously investigated SAM of Homocysteine (HCys)-pyridinedicarboxylic acid (PDCA) for selective sensing of the Hg 2 ions using a portable piezoresistive platform [39,40] and exper-imental results confirmed that proposed setup is capable of picomolar sensing. In this paper, we have used the previously designed portable piezoresistive platform to selectively capture the Cadmium ions in the picomolar range.…”