A modified selective optical sensor for selenium determination based on incorporating xylenol orange in a poly(vinyl chloride) membrane

• Published in: RSC advances 2023-11, Vol.13 (49), p.34618-34629
• Main Authors: Hassan, Abeer M. E, Alshehri, Reem F, El-Bahy, Salah M, Amin, Alaa S, Aish, Mai
• Format: Article
• Language: English
• Subjects: Biological materials; Chlorides; Membranes; Optical measuring instruments; Selenium; Sensors
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d3ra05308c

A novel optical sensor has been developed to measure selenium ions. The sensor membrane was created by mixing xylenol orange (XO) and sodium tetraphenylborate (NaTPB) with a plasticized poly(vinyl chloride) membrane that contained o -nitrophenyl octyl ether ( o -NPOE) as a plasticizer. XO was previously established for use in a colorimeter to measure selenium in water and other media. At pH 6.6, the color of the detecting membrane changed from orange to pink when in contact with Se 4+ ions. Various variables affecting the uptake efficiency were evaluated and optimized. Under optimum conditions ( i.e. , 30% PVC, 60% o -NPOE, and 5.0% of both XO and NaTPB for 5.0 min as the response time), the proposed sensor displayed a linear range 10-175 ng mL −1 with the detection and quantification limits of 3.0 and 10 ng mL −1 , respectively. Also, the precision (RSD%) was better than 2.2% for six replicate determinations of 100 ng mL −1 Se 4+ in various membranes. For the detection of Se 4+ , the selectivity of the sensor membrane was investigated for a number of possible interfering inorganic cations, but no appreciable interference was found. With the use of a 0.3 M HCl solution, the sensor was successfully restored, and the response that may have been reversible and reproducible exhibited an RSD% of less than 2.0%. The sensor has been successfully used to analyze Se 4+ ions in environmental and biological materials. Schematic representation for the preparation, complexation and regeneration of the formed optical sensor.