One-Step Fabrication of a Self-Driven Point-of-Care Device by Femtosecond Laser Direct Writing and Its Application in Cancer Cell H2O2 Detection via Semiconductor-Based SERS

Abstract Self-driven microfluidic systems have attracted significant attention and demonstrated great potential in the field of point-of-care (POC) testing due to their device simplicity, low power consumption, increased portability, and reduced sample consumption. To develop POC detection devices with diverse characteristics that meet different requirements, there is a strong demand for feasible strategies that enable easy operation and reduce processing time. Here, we proposed a one-step processing approach using femtosecond laser direct writing technology to fabricate a capillary-actuated POC microfluidic chip. The driving force of the chip is highly dependent on its surface wettability, which can be easily adjusted by changing the laser processing parameters. This POC microfluidic chip allowed for the detection of intracellular H2O2 through a catalytic reaction system that incorporated 5-aminosalicylic acid (5-Asa)-sensitized colloidal TiO2 nanoparticles and horse radish peroxidase (HRP), combined with the integration of semiconductor-based surface-enhanced Raman scattering (SERS) spectroscopy. The concentration of H2O2 was determined by the SERS signal of the catalytic products, resulting in rapid detection with minimal sample consumption. Our method provides a simple, feasible, and alternative strategy for fabricating self-driven POC devices, which was successfully applied to the rapid detection of intracellular H2O2 in MCF-7 breast cancer cells with high sensitivity and tiny sample consumption. This work not only demonstrates the exceptional advantages of femtosecond laser processing technology in fabricating diverse microfluidic devices for various applications, but also presents an efficient POC testing strategy for detecting cell signaling molecules and enabling early diagnosis of breast cancer.