Micro flow sensor on a chip for the determination of terbutaline in human serum based on chemiluminescence and a molecularly imprinted polymer

Based on a molecularly imprinted polymer (MIP) as the recognition element, a novel chemiluminescence (CL) micro flow sensor on a chip for the determination of terbutaline in human serum is described. The MIP was prepared by using terbutaline as the template, methacrylic acid (MAA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linking monomer, and acetonitrile as the solvent. The chip was fabricated from two 50 mm × 40 mm × 5 mm transparent poly (methylmethacrylate) (PMMA) slices. The microchannels on the chip etched by CO₂ laser were 200 μm wide and 150 μm deep. The microsensor cell filled with 2 mg MIP for selectively on line adsorbing terbutaline was 10 mm long, 1 mm wide, and 0.5 mm deep. All reagents were controlled by the syringe pump with an accurate timer. The on line adsorbed terbutaline by the MIP can enhance the CL intensity of the reaction of luminol with ferricyanide. The enhanced CL intensity is linear with terbutaline concentration from 8.0 to 100 ng/mL with a detection limit of 4.0 ng/mL (3σ). The micro flow sensor provides for good reproducibility with the relative standard deviation of 3.6% (n = 7) for 20 ng/mL terbutaline.