Controlled Au-coated PDMS microwell array for surface-enhanced DNA biochips†

Abstract

Microwell technology is crucial in biological applications due to its ability to handle small sample sizes and perform numerous assays efficiently. This study aimed to develop a novel technique for microwell fabrication using pressure-assisted steam technology, offering lower cost, simplicity, and high reproducibility. Mechanical properties of microwell surfaces were successfully controlled and characterized, making them suitable for DNA capture. The application of gold coating generated an electric field within designed microwells, facilitating stable DNA detection. These microwells exhibited effective DNA sensing capabilities, validated using fluorescently stained lambda DNA at various concentrations (86, 8.6, and 0.86 ng μL⁻¹). In particular, the 2.8 mm microwell showed a greater change in fluorescence intensity depending on DNA concentration than other microwells. At a concentration of 0.86 ng μL⁻¹, to assess producibility using relative standard deviation (RSD) values as a DNA sensor, they were measured as 5.29, 2.76, and 1.85% for 1, 1.7, and 2.8 mm microwells, respectively. These results indicated that our proposed microwell exhibited efficient performance and good reproducibility. We believe that the developed method could be potentially used for high-throughput analysis as a biosensor for DNA applications.