This review summarizes recent advancements in electrochemical sensors for formaldehyde detection. Formaldehyde, a common indoor air pollutant, poses significant environmental and health risks. Electrochemical sensors offer high sensitivity, selectivity, and real-time monitoring capabilities, making them ideal for formaldehyde detection. The review explores the fundamental principles, mechanisms, and diverse methodologies used in electrochemical formaldehyde detection, emphasizing the role of innovative sensing materials and electrodes. Recent developments in nanotechnology and sensor design have significantly enhanced the sensitivity and selectivity of these detection systems. The review also identifies current challenges and discusses future research directions, aiming to encourage ongoing research and innovation in this field to develop advanced, practical solutions for formaldehyde detection in various environmental and biological contexts. Electrochemical formaldehyde sensors can be categorized into two types: semiconductor-based sensors and solution reaction-based sensors. Semiconductor-based sensors rely on the reaction of formaldehyde with adsorbed oxygen on the surface of semiconductor materials, leading to changes in conductivity or voltammetric characteristics. Solution reaction-based sensors involve the chemical oxidation of formaldehyde at the electrode surface, resulting in a current or potential response. These sensors operate under milder reaction conditions and can be developed using various electrode materials and sensing modes. Enzymatic formaldehyde electrochemical sensors utilize enzymes such as formaldehyde dehydrogenase (FDH) and alcohol oxidase (AOX) for detection. These sensors rely on the catalytic activity of enzymes to oxidize formaldehyde, generating an electrical current that can be correlated with formaldehyde concentration. Electrochemical sensors based on electrocatalysts utilize inorganic metals or metal oxides to catalyze the oxidation of formaldehyde. These sensors offer high sensitivity and selectivity, making them suitable for formaldehyde detection. The review highlights the advantages of using noble metals such as gold (Au), platinum (Pt), and palladium (Pd) as electrocatalysts for formaldehyde detection. These metals exhibit high catalytic activity, stability, and electrochemical properties that enhance the performance of formaldehyde sensors. The review also discusses the application of various electrocatalysts, including metal oxides, hydroxides, and composite materials, in the development of electrochemical formaldehyde sensors. The study emphasizes the importance of optimizing the structure and properties of electrocatalysts to improve the performance of formaldehyde sensors. Overall, the review provides an overview of the latest advancements in electrochemical sensors for formaldehyde detection, highlighting the potential of these sensors in various environmental and biological applications.This review summarizes recent advancements in electrochemical sensors for formaldehyde detection. Formaldehyde, a common indoor air pollutant, poses significant environmental and health risks. Electrochemical sensors offer high sensitivity, selectivity, and real-time monitoring capabilities, making them ideal for formaldehyde detection. The review explores the fundamental principles, mechanisms, and diverse methodologies used in electrochemical formaldehyde detection, emphasizing the role of innovative sensing materials and electrodes. Recent developments in nanotechnology and sensor design have significantly enhanced the sensitivity and selectivity of these detection systems. The review also identifies current challenges and discusses future research directions, aiming to encourage ongoing research and innovation in this field to develop advanced, practical solutions for formaldehyde detection in various environmental and biological contexts. Electrochemical formaldehyde sensors can be categorized into two types: semiconductor-based sensors and solution reaction-based sensors. Semiconductor-based sensors rely on the reaction of formaldehyde with adsorbed oxygen on the surface of semiconductor materials, leading to changes in conductivity or voltammetric characteristics. Solution reaction-based sensors involve the chemical oxidation of formaldehyde at the electrode surface, resulting in a current or potential response. These sensors operate under milder reaction conditions and can be developed using various electrode materials and sensing modes. Enzymatic formaldehyde electrochemical sensors utilize enzymes such as formaldehyde dehydrogenase (FDH) and alcohol oxidase (AOX) for detection. These sensors rely on the catalytic activity of enzymes to oxidize formaldehyde, generating an electrical current that can be correlated with formaldehyde concentration. Electrochemical sensors based on electrocatalysts utilize inorganic metals or metal oxides to catalyze the oxidation of formaldehyde. These sensors offer high sensitivity and selectivity, making them suitable for formaldehyde detection. The review highlights the advantages of using noble metals such as gold (Au), platinum (Pt), and palladium (Pd) as electrocatalysts for formaldehyde detection. These metals exhibit high catalytic activity, stability, and electrochemical properties that enhance the performance of formaldehyde sensors. The review also discusses the application of various electrocatalysts, including metal oxides, hydroxides, and composite materials, in the development of electrochemical formaldehyde sensors. The study emphasizes the importance of optimizing the structure and properties of electrocatalysts to improve the performance of formaldehyde sensors. Overall, the review provides an overview of the latest advancements in electrochemical sensors for formaldehyde detection, highlighting the potential of these sensors in various environmental and biological applications.