Imprint Molding of a Microfluidic Optical Cell on Thermoplastics with Reduced Surface Roughness for the Detection of Copper Ions

Abstract

Here, we introduce a simple and facile technique for fabricating microfluidic optical cells by utilizing a micropatterned polymer mold, followed by imprinting on thermoplastic substrates. This process has reduced the surface roughness of the microchannel, making it suitable for microscale optical measurements. The micropatterned polymer mold was fabricated by first micromilling on a poly(methylmethacrylate) (PMMA) substrate, and then transferring the micropattern onto an ultraviolet (UV)-curable optical adhesive. After an anti-adhesion treatment of the polymer mold fabricated using the UV-curable optical adhesive, the polymer mold was used repeatedly for imprinting onto various thermoplastics, such as PMMA, polycarbonate (PC), and poly(ethyleneterephthalate) (PET). The roughness values for the PMMA, PC, and PET microchannels were approximately 11.3, 20.3, and 14.2 nm, respectively, as compared to those obtained by micromilling alone, which were 15.9, 76.8, and 207.5 nm, respectively. Using the imprint-molded thermoplastic optical cell, rhodamine B and copper ions were successfully quantified. The reduced roughness of the microchannel surface resulted in improved sensitivity and reduced noise, paving the way for integration of the detection module so as to realize totally integrated microdevices.

A Highly Sensitive Colorimetric Method for Copper Ions Detection Based on Controlling the Peroxidase-like Activity of Au@Pt Nanocatalysts

“…Therefore, the development of an accurate and rapid method for Cu 2+ detection was very important. Among various detection approaches, colorimetric methods [12][13][14] have been widely utilized for Cu 2+ measurements due to their obvious merits, such as low cost, simplicity, practicality, and observable by the naked eye. However, the sensitivity and selectivity need to be further enhanced.…”

Copper Ion Sensing

“…13 Wu and co-workers used the absorption of copper ions at around 800 nm (copper aquo complex) as a means of evaluating the performance of microfluidic optical cells. 14 As described above, copper ions are important metal ions, which are often analyzed for various purposes and by various methods. As such, the importance of copper ions in the field of analytical chemistry will remain unchanged.…”