Nile Blue chromoionophore-doped kappa-carrageenan for a novel reflectometric urea biosensor

摘要: Abstract A new optical urea biosensor based on urease (Urs) physically attached to a pH optode made from Nile Blue (NB) chromoionophore-doped kappa-carrageenan (KC) membrane is described in this paper. The immobilized Urs the surface catalyzed hydrolytic decomposition of into ammonium hydroxide, changed more basic condition, and resulted colour change sensor blue violet, which can be quantified reflectometrically using fibre optic reflectance spectrophotometer. linear relationship was perceived between intensity KC membrane-based concentration range 0.001–100 mM with detection limit calculated at 0.001 mM. response time 10 min, no significant discrepancy noted for results obtained direct analysis urine samples by both catalytic UV–vis spectrophotometric standard method p -dimethylaminobenzaldehyde (DMAB) reagent.