PDMS Microfluidic Device with an Integrated Optical Sensor for Determination of Zinc (II) in Pharmaceuticals: Toward the Production of Miniaturized Green Chemistry Analytical Systems

ABSTRACT

A simple miniaturized system was fabricated in general laboratory from polydimethylsiloxane (PDMS) according to a prototype casting and molding process permitting the construction of three-dimensional (3D) microchannel (100 µm i.d.) with T-type network, together with an integrated optical sensor for on chip detection. The fabricated device has been successfully applied as a green chemistry-compatible miniaturized analytical system for the determination of zinc (II) in pharmaceutical samples taking the advantage of the colorimetric reaction of zinc (II) and xylenol orange in acetate buffer at pH 5.5. The microfluidic device is a convenient way to quantify zinc (II) over a wide dynamic range, 0.2–2.5 µg mL⁻¹, with good linearity (R² 0.9940).

KEYWORDS:

• Green spectrometry
• miniaturized system
• PDMS
• zinc

ACKNOWLEDGMENTS

The authors thank the Commission on Higher Education of Thailand for financial support to do some part of this work in The University of Hull, United Kingdom and thank the Department of Chemistry, Thammasat University and The University of Hull for facilities in the laboratory.

Notes

^a S_a and S_b is standard deviation of intercept and slope, respectively.

^b LOD: Limit of detection by Miller's method.

^a 95% confidence at degree of freedom = 4.

An invited paper submitted to a special issue on Green Spectroscopy and Analytical Techniques, organized by Professor Miguel de la Guardia, of the Department of Chemistry, University of Valencia, Spain, and Professor Arabinda Kumar Das, of the Department of Chemistry, University of Burdwan, West Bengal, India.