Tracking of carcinoembryonic antigen in early stages of colorectal cancer by graphene quantum dots-Based electrochemical immunosensor and aptasensor
Tracking of carcinoembryonic antigen in early stages of colorectal cancer by graphene quantum dots-Based electrochemical immunosensor and aptasensor
Safoora Mohammadzadeh,1Mohammad Hassan Emami,2Samane Mohammadzadeh,3Fatemeh Maghool,4-,5-,6,*
1. Poursina Hakim Digestive Diseases Research Center, Isfahan University of Medical Sciences, Isfahan, Iran 2. Poursina Hakim Digestive Diseases Research Center, Isfahan University of Medical Sciences, Isfahan, Iran 4. Poursina Hakim Digestive Diseases Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
Introduction: Carcinoembryonic antigen (CEA) is one of the most widespread colorectal cancers (CRC) biomarker. However, this antigen has low concentration in early stages of CRC, which could not be detected by common methods. In this review, we discuss the sensitive method for detection of CEA in the early stage of CRC. Electrochemical method as a high sensitivity, rapid response, easy to use and low-cost method, could be useful for detection of low levels of CEA. Different types of nanomaterials such as quantum dots and nanoparticles have been used on support materials to achieve high conductivity and boost detection signal in electrochemical sensors. Graphene quantum dots (GQDs) because of high mobility of charge carriers, chemical inertness, low toxicity, large specific surface area, and attractive biocompatibility have great potential applications in electrochemical detection. High specific interaction of antigen-antibody in electrochemical immunosensors and high affinity and specificity of electrochemical aptasensors provide the specific analysis of CEA. In this review has been shown that physical-chemical properties of GQDs and GQDs composites improve sensitivity of electrochemical immunosensors and aptasensors signals for determination of CEA
Methods: Relevant English published studies were included in this review.
Results: N, S-graphene quantum dots@Au-polyaniline impedimetric immunosensor could be applied for the selective detection of CEA in the linear range of 0.5–1000 ng/mL with good limit of detection (LOD) of 0.01 ng/mL. In addition, quantitative detection of CEA has been achieved with nitrogen-doped graphene quantum dots/ PtPd bimetallic nanoparticles/ Au nanoparticles immunosensor. The antibody-conjugated nanocomposite intensify the sensitivity of electrochemical signal in broad dynamic range, with a LOD of 2 fg/mL for the detection of CEA.
Furthermore, sensitive electrochemical aptasensor based on graphene quantum dots ionic liquid nafion nanomatrix has been reported for the determination of CEA concentrations. Electrochemical signals of aptasensor in presence of CEA have improved and exhibited the best detection limit of 0.34 fg/mL. The quantitative determination of CEA was achieved with the best linear response in the 10.0 fg/mL to 200.0 ng/mL CEA concentration using sandwich type GQDs/Au/graphene aptasensor. Signal amplification of CEA sensing has been obtained by new constructed sandwich sensing platform is from linkage of CEA aptamer to hemin–G–quadruplex DNAzyme
Conclusion: Immunosensors and aptasensors based on graphene-quantom dots composites with broad linear range for detection of CEA could be applied for the detection of CEA in the early stages of CRC.