The article by Liu, Dong, and Chen (2012) provides a comprehensive review of graphene-based sensors for biological and chemical detection. Graphene, a two-dimensional carbon material with exceptional electrical, chemical, optical, and mechanical properties, has garnered significant interest for sensor applications since its first isolation in 2004. The authors discuss various types of graphene materials, including single-layer graphene (SLG), graphene oxide (GO), reduced graphene oxide (RGO), and graphene nanoribbons (GNRs), and their preparation methods such as mechanical cleavage, chemical vapor deposition (CVD), and chemical reduction. The review highlights the unique advantages of graphene in sensor applications, such as high carrier mobility, high electron transfer rate, excellent quenching of fluorescence, and high surface-to-volume ratio. It also covers the functionalization of graphene to enhance its sensing capabilities, including covalent and noncovalent methods. The article delves into the development of electrochemical sensors using graphene materials, focusing on detecting hydrogen peroxide, glucose, nucleic acids, and protein markers. For hydrogen peroxide detection, sensors using RGO-chitosan composites and enzyme mediators have shown low detection limits and wide linear ranges. Glucose detection is facilitated by the excellent sensing ability of RGO towards hydrogen peroxide, often mediated by enzymes like glucose oxidase (GOD). Nucleic acid detection is achieved through the electrochemical differentiation of nucleobases and DNAs, leveraging the high electrochemical activity of RGO. Protein marker detection, such as alpha-fetoprotein (AFP) and prostate-specific antigen (PSA), is enabled by label-free immunosensors and sandwich immunoreactions on RGO-modified electrodes. Overall, the article emphasizes the potential of graphene-based sensors for sensitive and selective detection in various biological and chemical applications, highlighting the need for further research to optimize their performance and expand their utility.The article by Liu, Dong, and Chen (2012) provides a comprehensive review of graphene-based sensors for biological and chemical detection. Graphene, a two-dimensional carbon material with exceptional electrical, chemical, optical, and mechanical properties, has garnered significant interest for sensor applications since its first isolation in 2004. The authors discuss various types of graphene materials, including single-layer graphene (SLG), graphene oxide (GO), reduced graphene oxide (RGO), and graphene nanoribbons (GNRs), and their preparation methods such as mechanical cleavage, chemical vapor deposition (CVD), and chemical reduction. The review highlights the unique advantages of graphene in sensor applications, such as high carrier mobility, high electron transfer rate, excellent quenching of fluorescence, and high surface-to-volume ratio. It also covers the functionalization of graphene to enhance its sensing capabilities, including covalent and noncovalent methods. The article delves into the development of electrochemical sensors using graphene materials, focusing on detecting hydrogen peroxide, glucose, nucleic acids, and protein markers. For hydrogen peroxide detection, sensors using RGO-chitosan composites and enzyme mediators have shown low detection limits and wide linear ranges. Glucose detection is facilitated by the excellent sensing ability of RGO towards hydrogen peroxide, often mediated by enzymes like glucose oxidase (GOD). Nucleic acid detection is achieved through the electrochemical differentiation of nucleobases and DNAs, leveraging the high electrochemical activity of RGO. Protein marker detection, such as alpha-fetoprotein (AFP) and prostate-specific antigen (PSA), is enabled by label-free immunosensors and sandwich immunoreactions on RGO-modified electrodes. Overall, the article emphasizes the potential of graphene-based sensors for sensitive and selective detection in various biological and chemical applications, highlighting the need for further research to optimize their performance and expand their utility.