A New Method for Heavy Metals and Aluminium Detection Using Biopolymer-Based Optical Biosensor

A biopolymer-based biosensor for heavy metals and aluminium (Al) detection was constructed with naturally occurring β-carotene in palm kernel oil used as the biological reporter. The biosensor was designed with β-carotene entrapped by polyurethane, a polymer formed through prepolymerization of palm kernel oil. The presence of copper (Cu), lead (Pb), zinc (Zn), and Al was detected through the emulsification of β-carotene, which caused the change of optical density (OD) at λ = 450 nm. The results showed the OD increased with the presence of heavy metals and Al within 0.1-10 mg/L. The biosensor was constructed without extra steps to immobilize the biological component and it was simple to use with one-step detection. Together with high reproducibility and fast response to heavy metals and Al within 15 min, the biosensor showed good potential to be developed as a method to detect the presence of heavy metals and Al.