This review highlights advancements in the identification and reduction of 4-Nitrophenol (4-NP), a toxic organic compound. It covers various detection methods, including electrochemical, optical fiber-based surface plasmon resonance, and photoluminescence techniques, as well as the mechanisms of Förster Resonance Energy Transfer (FRET) and Inner Filter Effect (IFE) in fluorescence detection. Removal techniques such as homogeneous, electrocatalytic, photocatalytic, and thermocatalytic methods are discussed, along with their reaction mechanisms. The review also delves into the theoretical perspectives of 4-NP detection and reduction, parameters influencing their activities, and future research directions. Organic and inorganic nanomaterials, such as carbon dots (CDs) and nanoparticles, have shown promise in selective detection and removal of 4-NP. Electrochemical techniques offer high selectivity and sensitivity, while photoluminescence methods are cost-effective and eco-friendly. Surface plasmon resonance with optical fibers provides high sensitivity and selectivity. The reduction of 4-NP involves various catalytic processes, including NaBH4-based reduction, electrocatalysis, photocatalysis, and thermocatalysis. The choice of method depends on the specific objectives and nature of the contaminants. The review concludes by emphasizing the need for further research to improve the efficiency and cost-effectiveness of 4-NP identification and removal methods, as well as the integration of preventive approaches to address the release of this contaminant into the environment.This review highlights advancements in the identification and reduction of 4-Nitrophenol (4-NP), a toxic organic compound. It covers various detection methods, including electrochemical, optical fiber-based surface plasmon resonance, and photoluminescence techniques, as well as the mechanisms of Förster Resonance Energy Transfer (FRET) and Inner Filter Effect (IFE) in fluorescence detection. Removal techniques such as homogeneous, electrocatalytic, photocatalytic, and thermocatalytic methods are discussed, along with their reaction mechanisms. The review also delves into the theoretical perspectives of 4-NP detection and reduction, parameters influencing their activities, and future research directions. Organic and inorganic nanomaterials, such as carbon dots (CDs) and nanoparticles, have shown promise in selective detection and removal of 4-NP. Electrochemical techniques offer high selectivity and sensitivity, while photoluminescence methods are cost-effective and eco-friendly. Surface plasmon resonance with optical fibers provides high sensitivity and selectivity. The reduction of 4-NP involves various catalytic processes, including NaBH4-based reduction, electrocatalysis, photocatalysis, and thermocatalysis. The choice of method depends on the specific objectives and nature of the contaminants. The review concludes by emphasizing the need for further research to improve the efficiency and cost-effectiveness of 4-NP identification and removal methods, as well as the integration of preventive approaches to address the release of this contaminant into the environment.