This study aims to develop a highly selective optical mesoporous conjugate adsorbent for efficient optical detection, sorption and extraction of cerium (Ce(III)) from waste effluents. The adsorbent was prepared by synthesizing of 4-tert-Octyl-4-((phenyl)diazenyl)phenol and subsequently successfully immobilized onto mesoporous silica monoliths. The data revealed that the conjugate adsorbent was efficiently detected and adsorbed the ultra-trace Ce(III) ions from aqueous solutions. Therefore, the present adsorbent based on novel ligand modified optical conjugate adsorbent offered a simple technique without using sophisticated instruments for Ce(III) detection, sorption and recovery systems. The solution pH was played an important role for detection and sorption but the present adsorbent worked well in acidic pH region at 3.50. Some important experimental conditions such as dosage of adsorbent, initial Ce(III) concentration, contact time, selectivity, reversibility and kinetics performances have been investigated. The detection limit and maximum sorption capacity of the adsorbent for Ce(III) at optimum conditions was 0.18 mu g/L and 192.31 mg/g, respectively. In addition, the adsorbent was reversible and kept remaining functionality to reuses in several cycles after extraction/elution process without significant deterioration in its original performances. Therefore, the design of optical conjugate adsorbent has a great potential to be used in efficient, selective and simultaneous Ce(III) detection, sorption and extraction from waste and can be used of nuclear power plants wastewaters treatment effectively. Large-scale studies are recommended to confirm these promising results of the laboratory scale. (C) 2013 Elsevier B.V. All rights reserved.