Smart Biosensors for Cancer Diagnosis Based on Graphene Quantum Dots

SIMPLE SUMMARY: Graphene quantum dots, the next generation of graphene family, due to their remarkable physical and chemical properties, have been shown to be ideal sensing elements for the early diagnosis of cancer. In this review, we report the recent advances in the synthesis and functionalization of GQDs with different biomolecules able to selectively recognize and convert into a signal specific cancer biomarker, by means of optical, electrochemical and chemiluminescent biosensors. These sensors have shown to ensure the effective and sensitive detection of important cancer biomarkers such as antigens, enzymes, hormones, proteins, cancer related byproducts, biomolecules exposed on the surface of cancer cells and also changes in pH. The developed biosensors can allow the effective diagnosis of cancer diseases as well as the evaluation of the anticancer therapy effectiveness. ABSTRACT: The timely diagnosis of cancer represents the best chance to increase treatment success and to reduce cancer deaths. Nanomaterials-based biosensors containing graphene quantum dots (GQDs) as a sensing platform show great promise in the early and sensitive detection of cancer biomarkers, due to their unique chemical and physical properties, large surface area and ease of functionalization with different biomolecules able to recognize relevant cancer biomarkers. In this review, we report different advanced strategies for the synthesis and functionalization of GQDs with different agents able to selectively recognize and convert into a signal specific cancer biomarkers such as antigens, enzymes, hormones, proteins, cancer related byproducts, biomolecules exposed on the surface of cancer cells and changes in pH. The developed optical, electrochemical and chemiluminescent biosensors based on GQDs have been shown to ensure the effective diagnosis of several cancer diseases as well as the possibility to evaluate the effectiveness of anticancer therapy. The wide linear range of detection and low detection limits recorded for most of the reported biosensors highlight their great potential in clinics for the diagnosis and management of cancer.