Polyvinyl alcohol–sodium alginate beads as a sensor for the detection of Cr(VI) in aqueous solution were developed by immobilizing 1,5–diphenylcarbazide. In the presence of Cr(VI), the color of beads sensor changed from yellowish-colorless into purplish-pink. Beads were prepared using polyvinyl alcohol–boric acid method. The resulted beads were characterized by FTIR spectrophotometer, and the absorbance
measurement was carried out at a wavelength of 547 nm. The optimum response of the beads sensing was obtained at pH 2, for 8 min sensing. The linearity of the calibration curve was obtained with a limit of detection for 25 mL sample was 0.11 mg L–1. The beads sensor had good precision, accuracy and also exhibited good stability for 30 d. Subsequently, the beads sensor was able to detect the presence of Cr(VI) in the water samples, proved by the color change of the beads sensor relative to the visual standards.
