Research on a New Micro-Volume Fluorescence Capillary Biosensor Assay for Sequentially Quantifying Pyruvate and Lactate.

It was studied that making conditions of a micro-volume fluorescence capillary biosensor for determining pyruvate (PA) and lactate (LA). The biosensor made under the optimized conditions could be used for sequential quantifications of LA in the range 0.10-1.2 mM and PA in 4-120 μM, and its recovery for PA and LA was in a satisfactory range 97-106% for human serum samples, with detection limits of 0.023 mM for LA (RSD < 1.89%, n = 11) and 0.87 μM for PA (RSD < 1.70%, n = 11). The new assay possessed these advantages that the LDH immobilizing on capillary realized the reuse of expensive enzyme in fluorospectrophotometry, and the consumption of serum samples or chemical reagents decreased to 9 μL in per assay, and the analytes no needed to preseparation, and it also are accurate and reliable. Consequently, the fluorescence capillary biosensor should have a good prospect in assaying PA and LA or LA/PA ratios for clinical medicines or biology field. The optimization conditions and parameters obtained in this study have also a certain guiding significance for the development of biochip based on glass substrate.