Non-invasive quantification of malondialdehyde biomarker in human exhaled breath condensate using self-assembled organic-inorganic nanohybrid: A new platform for early diagnosis of lung disease.

A novel electrochemical sensor was developed towards recognition of malondialdehyde (MDA) with modifying the glassy carbon electrode (GCE) by self-assembled riboflavin-taurine (RFPT) as organic substrate and silver nanoparticle (Ag NPs) as inorganic nano-catalyst. Therefore, a novel biocompatible and anti-bacterial substrate were prepared for the construction of electrode. In proposed sensor, the RF-PT polymer film led to the emergence of electroactive and suitable substrate for the immobilization of Ag NPs. The use of the proposed nano-hybrid significantly amplified the electrochemical signals the redox behavior was investigated using various electrochemical methods including cyclic voltammetry (CV), differential pulse voltammetry (DPV), square wave voltammetry (SWV), and linear sweep voltammetry (LSV). It is the adaptation of the established RF-PT-Ag NPs organic-inorganic hybrid for a selective, robust, and generalizable sensing system that is the emphasis of this work. The results show that the proposed platform has a good sensitivity in the detecting of MDA with a low limit of quantification (LLOQ) of 0.59 ± 0.05 μM. In addition, the modified electrode reveals promising efficiency against MDA oxidation and its side-products destructive effects. For the first time, the engineered sensor was used to non-invasive determination MDA in exhaled breath condensate (EBC) samples without the need to extra sample preparation steps. The results show RF-PT-AgNPs as a novel biocompatible interface can provide appropriate, reliable, in-expensive, fast, and user-friendly diagnostic tools in the detection of MDA in human real samples.