Electroactive Hemin-Cu-MOF nanocomposites driven ratiometric electrochemical aptasensor for sensitive Golgi protein 73 detection

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide. Early detection of HCC is pivotal for early treatment, thereby improving survival rates. Golgi protein 73 (GP73) is a promising biomarker for early HCC diagnosis, making it crucial to develop a sensitive method to detect GP73. In this study, a novel ratiometric electrochemical aptasensor was fabricated for the sensitive detection of GP73 using Hemin-Cu-based metal-organic framework (Hemin-Cu-MOF) nanocomposites and GP73 aptamers. The Hemin-Cu-MOF nanocomposites possessed not only excellent electroactive property with the Hemin and Cu-MOF as dual signal outputs, but also good electroconductivity to amplify the electrochemical signals. The Hemin-Cu-MOF nanocomposites with numerous active sites was used to label the GP73 aptamer (AptI) and construct the Hemin-Cu-MOF-AptI signal probe. Another sulfhydryl-modified GP73 aptamer (AptⅡ) was immobilized on the gold nanoparticles (Au) modified screen-printed carbon electrode (Au/SPCE) through gold-sulfur (Au-S) bonds and used as a capture probe. Upon adding GP73, AptI and AptⅡ specifically recognized GP73 to form the sandwich complex AptⅡ@GP73@Hemin-Cu-MOF-AptI, making the dual signal of Hemin-Cu-MOF change and indicating GP73 level. Under optimal experimental conditions, the ratio of two oxidation peak currents (I Cu-MOF /I Hemin ) was proportional to the GP73 concentration (1.0–300.0 ng/mL), with a detection limit as low as 0.625 ng/mL. Furthermore, the aptasensor was tested in real human serum samples using the standard recovery method, with recoveries ranging from 104.10 % to 116.66 %. Thus, the proposed aptasensor has great potential in clinical analysis for detecting GP73 and early diagnosing of HCC.