Fe/Pt-doped carbon nanoparticles with peroxidase-like activity for point-of-care determination of uric acid

Mikrochim Acta. 2024 Dec 21;192(1):20. doi: 10.1007/s00604-024-06861-9.

Abstract

A pasting-3D microfluidic paper-based analytical device (P-3D μPAD) was developed. It enabled an efficient cascade reaction between urate oxidase (UOX) and Fe/Pt-doped carbon nanoparticles (Fe/Pt-CNPs) for visual colorimetric detection of uric acid (UA). The novel Fe/Pt-CNP nanozyme performed high peroxidase-like activity toward 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2 with Michaelis - Menten constants (Km) of 0.97 and 2.30 mM, respectively. The UOX-Fe/Pt-CNP system was incorporated into P-3D μPAD: the 1st layer was UOX hydrolysis reaction under alkaline pH, and the 2nd layer was Fe/Pt-CNPs catalyzing H2O2 to oxidize TMB at acidic pH. The separated two layers allowed cascade reaction under different working pH without sacrificing the activity of UOX or Fe/Pt-CNPs. The images were captured and analyzed by the camera and "Color Recognition" application using a smartphone. The linear range of P-3D μPAD for UA was 25-1000 μM with a limit of detection of 10 μM which met the requirements for clinical applications. The high accuracy of P-3D μPAD for UA detection in invasive (blood) and noninvasive (saliva) samples has been confirmed by the biochemical analyzer. This work offers a sensitive, flexible, affordable, and disposable tool for on-site UA level monitoring and provides new insight into natural enzyme and nanozyme tandem systems for biosensing.

Keywords: Cascade reaction; Noninvasive and invasive biofluids; Pasting-3D microfluidic paper-based analytical device; Smartphone color recognition; Peroxidase-like nanozyme.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzidines* / chemistry
  • Biosensing Techniques / methods
  • Carbon* / chemistry
  • Colorimetry* / methods
  • Humans
  • Hydrogen Peroxide* / chemistry
  • Iron* / chemistry
  • Limit of Detection*
  • Nanoparticles* / chemistry
  • Peroxidase / chemistry
  • Platinum* / chemistry
  • Point-of-Care Systems
  • Urate Oxidase* / chemistry
  • Uric Acid* / blood
  • Uric Acid* / chemistry

Substances

  • Uric Acid
  • Carbon
  • Platinum
  • Urate Oxidase
  • Iron
  • Benzidines
  • Hydrogen Peroxide
  • 3,3',5,5'-tetramethylbenzidine
  • Peroxidase