An enhanced photoelectrochemical biosensor for colitoxin DNA based on HKUST-1/TiO2 and derived HKUST-CuO/TiO2 heterogeneous composites

Mikrochim Acta. 2021 Sep 8;188(10):328. doi: 10.1007/s00604-021-04999-4.

Abstract

HKUST-1 MOFs and its derivative HKUST-CuO were coupled with TiO2 nanoparticles to form the heterogeneous composites of HKUST-1/TiO2 and HKUST-CuO/TiO2 based on their well-suitable bandgap energies (Eg). Compared with mono-component HKUST-1 or HKUST-CuO, the prepared composites displayed photoelectrochemical (PEC) response due to the synergistic effect from their heterogeneous structure. Higher photocurrent response was obtained on HKUST-CuO/TiO2-modified ITO electrode (HKUST-CuO/TiO2/ITO), which could be attributed to the hollow structure with a thin shell of HKUST-CuO greatly enhancing visible spectra harvesting. The CuO component in HKUST-CuO not only could accelerate electron transfer on the heterojunction interface but also effectively separate the photo-generated charge carriers (e-1/h+). Based on the excellent PEC performance of prepared photoactive composite material, under visible-light excitation (λ ≥ 420 nm) and with a working potential of 0 V (vs. Ag/AgCl), the S1 (probe DNA)/HKUST-CuO/TiO2/ITO PEC platform was successfully fabricated for colitoxin DNA detection without using ascorbic acid (AA) as an electron donor. Compared with the analysis results on S1/HKUST-1/TiO2/ITO electrode, S1/HKUST-CuO/TiO2/ITO displayed a wider linear response range from 1.0 × 10-6 to 4.0 × 10-1 nM with a lower detection limit of 3.73 × 10-7 nM (S/N = 3), the linear regression equation was ΔI (10-6 A) =0.5549-0.1858 log (CS2/M), which confirmed the HKUST-CuO could improve sensitivity because of its prominent PEC property. The relative standard deviation (RSD) of the PEC sensor for target DNA detection of 2.0 × 10-4 nM was 7.4%. The proposed DNA biosensor also possessed good specificity and stability. Hence, this reported work was a promising strategy for molecular diagnosis in the bio-analysis field. (A) Schematic illustration of the preparation process of the proposed PEC biosensors for colitoxin DNA detection. (B) The preparation process of HKUST-1 and HKUST-CuO.

Keywords: DNA biosensor; HKUST-1; HKUST-CuO; Heterogeneous composite nanoparticles; MOF derivative; Photoelectrochemical detection.

MeSH terms

  • Bacterial Toxins / genetics
  • Biosensing Techniques / instrumentation
  • Biosensing Techniques / methods*
  • Copper / chemistry*
  • Copper / radiation effects
  • DNA / analysis*
  • DNA Probes / chemistry
  • Electrochemical Techniques / instrumentation
  • Electrochemical Techniques / methods*
  • Electrodes
  • Escherichia coli / chemistry
  • Escherichia coli Proteins / genetics
  • Immobilized Nucleic Acids / chemistry
  • Light
  • Limit of Detection
  • Metal Nanoparticles / chemistry
  • Metal Nanoparticles / radiation effects
  • Metal-Organic Frameworks / chemistry*
  • Metal-Organic Frameworks / radiation effects
  • Photochemical Processes
  • Titanium / chemistry*
  • Titanium / radiation effects

Substances

  • Bacterial Toxins
  • DNA Probes
  • Escherichia coli Proteins
  • Immobilized Nucleic Acids
  • Metal-Organic Frameworks
  • bis(1,3,5-benzenetricarboxylate)tricopper(II)
  • titanium dioxide
  • Copper
  • DNA
  • Titanium
  • cupric oxide