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Updated: Oct 26, 2025
Fluorescence-based Monitoring of PAD4 Activity via a Pro-fluorescence Substrate Analog
Published on: November 5, 2014
A fluorescent and colorimetric dual-channel sensor based on acid phosphatase-triggered blocking of internal
Fanpeng Ran1, Chen Ma1, Yueci Xiang1
1State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China.
Abstract:
A colorimetric and fluorescent dual-channel detection method for acid phosphatase (ACP) activity has been constructed, based on the internal filtering effect between oxidized 3,3',5,5'-tetramethylbenzidine (oxTMB) and rhodamine B (RB). Au3+, which in situ form gold nanoparticles (AuNPs), can oxidize colorless 3,3',5,5'-tetramethylbenzidine (TMB) to oxTMB (blue color). The fluorescence of RB can be quenched by oxTMB due to the spectral overlap of emission of RB and absorption of oxTMB. By means of the above process, ACP can be determined because ACP promotes the hydrolysis of 2-phospho-L-ascorbic acid trisodium salt (AAP) to generate ascorbic acid (AA), which can inhibit the internal filtering effect between RB and oxTMB. No material preparation was needed for the determination of ACP. The colorimetric and fluorimetric methods can quantify ACP in the range 0.06-5.0 mU/mL and 0.03-5.0 mU/mL, respectively. Furthermore, a smartphone-assisted sensing platform has been constructed for on-site monitoring of ACP in the range 0.75-50 mU/mL, and the detection limit is 0.3 mU/mL. The methods developed can measure ACP in human serum successfully.
