Design of a label-free aptasensor for electrochemical determination of hemoglobin: investigation of the peroxidase-like activity of hemoglobin for the sensing of different substrates

• Published in: Analyst (London) Vol. 148; no. 16; pp. 3899 - 398
• Main Authors: Teniou, Ahlem, Rhouati, Amina, Rabai, Selma, Catanante, Gaëlle, Marty, Jean-Louis
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 07.08.2023
• Subjects: Analytical chemistry; Bacteriology; Biocompatibility; Biodiversity and Ecology; Biomarkers; Biotechnology; Carbon; Catalytic activity; Electrical measurement; Electrodes; Environmental Sciences; Hemoglobin; Hydrogen peroxide; Labels; Life Sciences; Microbiology and Parasitology; Nanoparticles; Peroxidase; Square waves; Substrates
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/d3an00345k

The unbalanced hemoglobin level in biological fluids can cause several diseases; hence it can be used as a biomarker for diagnosis. We aim, in the present study, to construct a label-free electrochemical aptasensor for the quantification of hemoglobin. For that, a conjugate of l -cysteine and gold nanoparticles was used for the aptamer immobilization on screen printed carbon electrodes. Using square wave voltammetry, the calibration plot was obtained and it was linear in the range of 50 ng ml −1 to 36 000 ng ml −1 while the detection limit was 1.2 ng ml −1 . After the binding of Hb on the modified screen-printed carbon electrode surface, the peroxidase-like activity of the bound hemoglobin was explored in the quantification of different substrates. Hydrogen peroxide and nitrite were chosen as model analytes. Amperometric measurements showed wide linear ranges: 0.2 μM-7.7 mM and 3.6 nM-1.3 mM for H 2 O 2 and nitrite, respectively, with detection limits of 0.044 μM and 0.55 nM. In the proposed strategy, the aptamer provides excellent orientation and a biocompatible environment for hemoglobin whose catalytic activity plays a key role in H 2 O 2 and nitrite analysis. An aptasensing platform was employed for Hb determination. The catalytic activity of the bound Hb was explored by measuring H 2 O 2 and nitrite. The developed platform was highly sensitive and selective.