This paper presents the construction and characterization of an amperometric immunosensor based on the graphene/gold nanoparticles (AuNPs/GO) nanocomposite for the detection of the bladder cancer biomarker, apolipoprotein A1 (Apo-A1). The morphological analysis of the AuNPs/GO nanocomposite demonstrated an almost spherical shape of AuNPs and the successful coverage of their surface by graphene oxide. An increased G peak and decreased D peak after the association of AuNPs with GO, implied a reduction in graphene defects. The X-ray photoelectron spectroscopy (XPS) indicated a significant decrease in the quantity of oxygen-containing functional groups in the AuNPs/GO nanocomposite, as compared to the original GO. Furthermore, the developed sensor demonstrated commendable sensitivity and selectivity, with a wide linear range for Apo-A1 detection. Importantly, the immunosensor exhibited remarkable stability over a period of 14 days, signifying its potential for practical applications.

Construction of grapheneAuNPs based amperometric immunosensor for detecting bladder cancer biomarker apolipoprotein A1
    Abstract
    1 Introduction
    2 Experimental
        2.1 Materials
        2.2 Preparation of GO
        2.3 Preparation of AuNPsGO nanocomposite
        2.4 Preparation of immunosensor
        2.5 Determination of Apo-A1
    3 Results and discussion
    4 Conclusion
    References

• Jing Yang(Harbin Medical University Cancer Hospital, Harbin 150000, Heilongjiang Province, China)
• Xingyuan Wang(Harbin Medical University Cancer Hospital, Harbin 150000, Heilongjiang Province, China)
• Tingting Zhou(Harbin Medical University Cancer Hospital, Harbin 150000, Heilongjiang Province, China)
• Liangjun Wei(Harbin Medical University Cancer Hospital, Harbin 150000, Heilongjiang Province, China)
• Meiling Guo(Harbin Medical University Cancer Hospital, Harbin 150000, Heilongjiang Province, China)
• Yanan Liu(Harbin Medical University Cancer Hospital, Harbin 150000, Heilongjiang Province, China)
• Xiaoqi Sun(Harbin Medical University Cancer Hospital, Harbin 150000, Heilongjiang Province, China)
• Yanjie Wang(Harbin Medical University Cancer Hospital, Harbin 150000, Heilongjiang Province, China)