Novel sensor for the determination of CA 15-3 in serum of breast cancer patients based on Fe–gallic acid complex doped in modified cellulose polymer thin films

Abstract

Fe–gallic acid MOF embedded in an epoxy methyl cellulose polymer (CMC) thin film was synthesized and characterized by different micro-analytical tools such as: FE-SEM/EDX, XPS analysis, XRD analysis, FT-IR, and fluorescence spectroscopy. Fe–gallic acid MOF doped in a stable CMC polymer thin film is used as a novel sensor to identify CA 15-3 in the sera of patients suffering breast malignancy. The presence of appropriate functional groups in aqueous CA 15-3 solutions enables it to interact with the Fe–gallic acid MOF embedded in the thin film. The Fe–gallic acid MOF was found to absorb energy at 350 nm (λ_ex) and emits radiation at 439 nm which was specifically quenched in the presence of CA 15-3 over a working concentration range of 0.05–570 U mL⁻¹. In contrast to other CA 15-3 detection methods which suffered from electronic noise, interference and slowness, the Fe–gallic acid MOF proved its sensitivity as an economic, stable and reliable probe for the detection and determination of CA 15-3 in patients' serum samples with a detection limit of 0.01 U mL⁻¹ at pH 7.2.