A dual-mode immunosensor for detection of oncoprotein c-Myc via indirect competition using trimetallic nanocomposite as an excellent label.

BACKGROUND

The expression of oncoprotein c-Myc (OPc-Myc) in blood is closely related to the occurrence and development of various tumors. Common detection methods have the disadvantages of complicated procedures, expensive instruments, or low sensitivity. Currently, several single-mode immunosensors have been developed to detect OPc-Myc and overcome the above shortcomings. However, they are susceptible to the interference of the sensing interface and the external environment, which may lead to false-positive or false-negative results. Therefore, sensitive and accurate assessment of OPc-Myc levels in the blood is very important for the early diagnosis and monitoring of tumors.

RESULTS

A novel electrochemiluminescence (ECL)-electrochemical (EC) dual-mode immunosensor was developed for the sensitive detection of trace OPc-Myc. Gold nanoparticles-magnetic reduced graphene oxide (AuMrGO), with a large surface area and conductivity, were stably fixed on a magnetic glassy carbon electrode and utilized as the immobilization platform. Ruthenium(II)tris(bipyridine) (Ru) doped Au, Ag, and Pd trimetallic nanocomposite (Tri-Ru) with excellent ECL and EC properties was synthesized by mechanical alloying method and used as the bifunctional signaling label. Further, combined with the trace detection advantages of indirect competition, the convenient and sensitive dual-mode detection of OPc-Myc was realized. The results showed a strong linear relationship for concentrations from 10 pg L-1 to 0.1 μg L-1 in ECL mode and from 0.1 ng L-1 to 1 μg L-1 in EC mode, with limits of detection (LOD) of 4.9 pg L-1 and 30 pg L-1, respectively. The assay performed good analytical performances and clinical practicability in lymphoma patients' blood samples.

SIGNIFICANCE: This is the first detection of OPc-Myc using an ECL immunosensor, and it is also the first attempt to use a dual-mode detection strategy for OPc-Myc. The strategy could be used for sensing and detecting other proteomic tumor markers and established a promising platform for early auxiliary diagnosis and monitoring of cancers.