Bovine Serum Albumin Protein-Based Liquid Crystal Biosensors for Optical Detection of Toxic Heavy Metals in Water

• Published in: Sensors (Basel, Switzerland) Vol. 20; no. 1; p. 298
• Main Authors: Amin, Noor Ul, Siddiqi, Humaira Masood, Kun Lin, Yang, Hussain, Zakir, Majeed, Nasir
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 05.01.2020; MDPI
• Subjects: Ammonium chloride; Animals; Biosensing Techniques; Biosensors; Body fluids; bovine serum albumin; Cattle; Chloride; Copper; heavy metal ions; Heavy metals; Humans; Liquid crystals; Liquid Crystals - chemistry; Metal ions; Metals, Heavy - isolation & purification; Metals, Heavy - toxicity; Nitrates; Nitrogen; Optical microscopes; Optimization; Organisms; polarized optical microscope; Reproducibility; Sensors; Serum albumin; Serum Albumin, Bovine - chemistry; Water - analysis; Water - chemistry; United States > US; Singapore; liquid crystals; polarized optical microscope; heavy metal ions; bovine serum albumin
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s20010298

A new methodology involving the use of Bovine Serum Albumin (BSA) as a probe and liquid crystal (LC) as a signal reporter for the detection of heavy metal ions in water at neutral pH was developed. BSA acted as a multi-dentate ligand for the detection of multiple metal ions. The LC sensor was fabricated by immobilizing 3 µg mL BSA solution on dimethyloctadecyl-[3-(trimethoxysilyl)propyl]ammonium chloride (DMOAP)-coated glass slides. In the absence of heavy metal ions, a dark optical image was observed, while in their presence, a dark optical image turned to bright. The optical response was characterized by using a polarized optical microscope (POM). The BSA based LC sensor selectively detected toxic metal ions as compared to s block metal ions and ammonium ions in water. Moreover, the limit of detection was found to be very low (i.e., 1 nM) for the developed new biosensor in comparison to reported biosensors.