A new Schiff base chemosensor (2,2′-(1E,1′E)-(hexane-1,6-diylbis(azan-1-yl-1-ylidene))bis(methan-1-yl-1-ylidene)diphenol) was synthesized (denoted as C6) and characterized by NMR, ESI–MS and FTIR analysis. C6 was screened against several toxic and hazardous materials including heavy metals via spectrophotometry, and Cr+3 was found to produce a distinctive hyperchromic shift in the absorbance of C6. Further analytical evaluation to decipher the supramolecular interaction between C6 and Cr+3 showed that C6 acted as selective chemosensor and exhibited high sensitivity toward Cr+3 in the presence of a wide range of other metal ions. The limit of detection for Cr+3 by using C6 via spectrophotometric detection was found to be around 10 µM. Furthermore, a chemosensing protocol was successfully utilized to recognize Cr+3 in real samples of tap water. Hence, C6 provides a rapid, sensitive and robust method for the detection and possible removal of Cr+3 from aqueous solution and holds potential for its monitoring in the environment.