posted on 2023-11-03, 17:03authored byMozammal
Md Hossain, Md Mobarok Karim, Kyeong-Deok Seo, Deog-Su Park, Yoon-Bo Shim
A disposable
microfluidic channel sensor printed on a plastic platform
was developed to analyze heavy metal ions (HMIs) as a model target
species. Precise separation and detection of multiple targets were
established by symmetrically applying a small AC potential on the
carbon channel walls to induce an electrodynamic force. The separation
device was constructed by covering it with a plastic lid to achieve
capillary action in the channel. The sample flow rate was regulated
by the hydrophilicity of the lid plastic and electrodynamic convection
by the AC field, which was characterized by the contact angle measurement
and the additional electrodynamic force. The flow variables and their
relevance to the capillary phenomena were demonstrated, and the analytical
parameters were optimized. The working electrode was modified with
poly(diamino terthiophene) anchored with nanosized graphene oxide
(pDATT/GO) to enhance the detection performance. The experimental
variables for separating and detecting the target species were optimized
according to the AC frequency and amplitude, sample flow rate, electrolytes,
pH, temperature, and applied potential for detection. The linear dynamic
ranges were between 0.1 and 200.0 ppb, with detection limits of 0.04
± 0.023, 0.29 ± 0.05, 0.07 ± 0.011, and 0.14 ±
0.06 ppb for Cu2+ Cd2+, Hg2+, and
Pb2+, respectively. Finally, the reliability of the proposed
method was evaluated through analysis of HMIs in real water samples.
The results were matched to those obtained through parallel analysis
using ICP–MS at a 95% confidence level.