A high-Throughput fluorimetric microarray with enhanced fluorescence and suppressed "coffee-ring" effects for the detection of calcium ions in blood

Abstract

A rapid, ultrasensitive, and high-Throughput fluorimetric microarray method has been developed using hydrophobic pattern as the microarray substrate and 3-Aminopropyltriethoxysilane-coupled carboxylic acid calcium (APS-CCA) as the fluorescent probes for sensing Ca 2+ ions in blood. The hydrophobic pattern of the developed Ca 2+ analysis microarray could largely suppress the "coffee-ring" effects to facilitate the better distribution density of testing microspots toward the high-Throughput detections, and especially prevent the cross-contamination of the multiple samples between adjacent microspots. Moreover, the use of APS matrix could endow the CCA probe the enhanced environmental stability and fluorescence intensity, which is about 2.3-fold higher than that of free CCA. The interactions between APS-CCA and Ca 2+ ions were systematically characterized by UV-vis and fluorescence measurements including microscopy imaging. It was demonstrated that the fluorimetric microarray could display the strong capacity of specifically sensing Ca 2+ ions with the minimal interferences from blood backgrounds. Such an APS-CCA-based fluorimetric microarray can allow for the analysis of Ca 2+ ions down to 0.0050 mM in blood, promising a highly sensitive and selective detection candidate for Ca 2+ ions to be applied in the clinical laboratory.