A comparative study of conventional spectroscopic techniques versus a miniaturized lab-on-a-chip platform for captopril analysis

Microfluidic devices have special benefits for developing effective drug tests and screening. The microfluidic platforms may provide a less expensive and faster alternative. Fluid-containing devices are quite large on a micrometer scale. Drug assay levels are modest (milliliters to femtoliters) as a result of this strict constraint. In this study, a carbon dioxide (CO₂) laser machine was used to build a microfluidic chip with micro-channels carved on substrate materials made of acrylic (polymethyl methacrylate, or PMMA). The breadth, depth, and roughness of the chip are influenced by the CO₂ parameters. Low roughness and a regular channel surface are achieved by using the laser power (60 W).permits us to obtain microchannels with a minimum diameter of 450 µm and a depth of 89.4 µm at a scanning speed of 250 m/s. The channels’ depth was 89.4 µm, and their surface roughness was measured with high precision and good surface quality using the Arithmetic Average Roughness Ra = 2.3 (Relative roughness, ̐ = 5 %). To detect extremely low levels of captopril, the drug signal was enhanced using functionalized multi-walled carbon nanotubes (F-MWCNTs). In this study, laser microfluidic sensors outperform the conventional method (UV–VIS) spectrophotometer in terms of captopril detection accuracy. The linear range of the microfluidic sensors is 1–20 ppm, whereas the linear range of the UV–VIS spectrophotometer is 10–90 ppm. The LOD is 1.3 and 0.1, respectively.