Detection of Pyrophosphate and Alkaline Phosphatase Activity Based on PolyT Single Stranded DNA - Copper Nanoclusters

Abstract

The determination of pyrophosphate and alkaline phosphatase activity plays a signi cant role in medical diagnosis. In this work, a label-free "ON-OFF-ON" uorescence strategy is developed for the analysis of pyrophosphate and alkaline phosphatase activity. Using PolyT single strand DNA as templates to synthesize uorescent copper nanoparticles, the coordination effect of pyrophosphoric acid on Cu 2+ inhibited the generation of uorescence. Afterwards, the addition of alkaline phosphatase into hydrolyze pyrophosphoric acid resulted in the release of Cu 2+, whereby the uorescence intensity could be recovered. Thereupon enhanced-sensitivity for alkaline phosphatase was obtained (0.1 mU/L), much better than previously reported methods. Meanwhile, it could be performed directly in homogeneous solution, which was very close to the actual activity level of alkaline phosphatase under physiological conditions. Likewise, satisfactory results were also obtained in speci city assessment, which demonstrated its potential application in clinical diagnosis. Notably, a new, sensitive, low-cost, short-time, and high-sensitivity platform for alkaline phosphatase detection was constructed, and the design of biosensor using DNA-templated Copper nanoclusters (CuNCs) was instructed in this study.

Chromogenic Mechanisms of Colorimetric Sensors Based on Gold Nanoparticles

“…In recent years, more and more metallic nanomaterials have been used for the construction of colorimetric sensors, such as gold/silver nanospheres (Au/Ag NSPs), gold nanorods (Au NRs), gold/silver nanotriangles (Au/Ag NPLs), gold nano-bipyramids (Au NBPs), gold nanostars (Au NSs), copper nanoclusters (Cu NCs) and iron tetroxide nanoparticles (Fe 3 O 4 ), which have been widely used for the detection and analysis of life-related substances and chemical contaminants due to their unique physical and chemical properties [ 5 , 6 , 7 , 8 , 9 , 10 ]. Among them, gold nanoparticles (Au NPs) are widely used in the construction of colorimetric sensors because of their tunable localized surface plasmon resonance (LSPR), high stability, biocompatibility and easy modification [ 11 ].…”