Robust and reliable detection of malondialdehyde in biological samples via microprobe-triggered surface-enhanced Raman spectroscopy

Malondialdehyde (MDA) is an endogenous genotoxic product of lipid peroxidation and its accumulation in the human body is associated with various diseases. To accurately understand the role of MDA in physiological and pathological processes, it is of great significance to develop a robust and reliable method for rapid detection of MDA. Hence, we proposed a surface-enhanced Raman spectroscopy (SERS) based method for MDA analysis, which employed 4-aminophenylthiophenol (PATP) as a SERS microprobe to recognize and quantify MDA. Qualitative analysis of MDA was performed using the fingerprint Raman spectrum of MDA adducts, and quan-titative analysis of MDA was conducted using the characteristic peak of PATP at 1083 cm-1 as the internal standard. MDA detection can be performed in a mild reaction environment and the detection limit was below 0.50 mu M. The proposed method successfully detected MDA in fresh blood samples and found satisfactory recovery rates in spiked samples. The proposed method allows reliable detection of endogenous toxic compounds in blood plasma, which is of great significance for monitoring oxidative stress indicators, such as lipid peroxidation rate and intensity, potential antioxidant capacity, and the degree of tissue peroxidation damage.