In Situ Enzymatic Generation of Gold Nanoparticles for Nanozymatic Label-free Detection of Acid Phosphatase

Abstract

Pronounced changes of acid phosphatase (ACP) in the human body may occur because of several diseases. Unusual ACP expressions might be diagnostically useful as serological and histological biomarkers for specific conditions and for investigations into the pathophysiology of their associated diseases. Recently, artificial enzyme-based colorimetric detection has garnered increased research interest because of its practicability, cost-effectiveness, and flexibility in use. Herein, for the first time, a label-free sensitive visual detection of ACP is proposed based on a signal transduction strategy in conjunction with an enzyme cascade reaction and the nanozymatic activity of the in situ synthesized gold nanoparticles (Au NPs). The ACP-catalyzed hydrolysis of L-ascorbic acid 2-phosphate sesquimagnesium (AAPS) generates ascorbic acid (AA), which in turn reacts with HAuCl 4 to generate Au NPs. The nonenzymatic activity of the synthesized Au NPs toward 3,3′,5,5′-tetramethylbenzidine (TMB) and H 2 O 2 produces a visual readout color that may be utilized to effectively determine ACP concentrations in biological media. The terephthalic acid test confirmed that the size of the Au NPs played a significant role in the nonenzymatic reaction. The quantitative sensing of ACP activity over a wide linear range (0.01−50 mU mL −1 ) with a detection limit of 0.03 mU mL −1 was realized, which endowed the proposed method with high sensitivity for potential real-life applications. Moreover, the present detection approach demonstrated higher sensitivity than a commercially available ACP kit. The approach reported in this study opens a prospect for label-free amplified colorimetric assays of enzymes and biomarkers.

Rational Integration of Nanozyme Probe and Smartphone Device for On‐Site Analysis

“…Acid phosphatase (ACP) is another crucial biomarker of multiple diseases, including kidney disease, hepatitis, prostatitis, and hematological system diseases. [114,115] Consequently, it is also of great significance to monitor ACP for early diagnosis of related diseases. Using histidine-doped NÀ Mn 3 O 4 NPs with OXD-like activity, Yue and co-workers proposed a dual-mode detection method for ACP content based on colorimetric and ratiometric fluorescence methods with a smartphone.…”

“…Acid phosphatase (ACP) is another crucial biomarker of multiple diseases, including kidney disease, hepatitis, prostatitis, and hematological system diseases [114,115] . Consequently, it is also of great significance to monitor ACP for early diagnosis of related diseases.…”

Surface modification strategies and the functional mechanisms of gold nanozyme in biosensing and bioassay

“…As an energetically favored facet for a peroxidase reaction, the (100) facet has the most stable transition state [ 22 ]. Another facet with peroxidase activity is the (211) [ 29 ]. For this type of reaction, an acidic environment is needed which protonate the surface of GNZs, with Bronsted-Lowry protons and enhance the transition state stability.…”

Single-step colorimetric detection of acid phosphatase in human urine using an oxidase-mimic platinum nanozyme

“…3,9–11 These sensors require relatively inexpensive instrumental set-up and are simple to use in terms of sample preparation, sensor operation, and sensor read-out. 12,13 Of these, the use of colorimetric signals for detection is desirable as it allows the incorporation of digital tools including a smartphone photo for image analysis and automation. 14–16…”