Laser-fabricated wood-based microfluidic chip integrating dual detection for lead ion detection

This study utilized laser processing to prepare a wood-based microfluidic chip incorporating two detection methods (microwave detection and colorimetric spectroscopy detection) for detecting lead ions in solutions. By optimizing CO₂ and femtosecond laser processing parameters and ultraviolet bonding processes, preparation of the chip was achieved. Femtosecond laser processing created 5.285 µm capacitive gaps in resistor-inductor-capacitor (RLC) resonant circuits. RLC circuits and a sodium rhodizonate colorimetric method were used to detect lead ions in solutions. Experimental results showed that the dual-mode system exhibited detection limits of 1 µg/L (colorimetry, linear response at 620 nm, ) and 10 µg/L (microwave sensing via the peak frequency changes between 2.5 and 3.2 GHz, with a sensitivity of 0.36 dB/10 µg/L). This study accomplished the precision manufacturing of a wood-based microfluidic chip through laser processing and realized the integration of microwave and spectroscopic detection technologies.