Optical biosensor based on nitrite reductase immobilised in controlled pore glass

Spherical vs. Granular Immobilization Support Selection and Performance on an Optical Flow Cell Immunosensor Based on the Fluorescence of Cyanine‐5

“…In the CPG(-NCS) 16.5 mg AP g 21 of support were immobilized, a value lower than the 19.3 mg AP g 21 of support obtained in the TRISO(-NCS) 47.8 nm. These values were lower than the 57.0 mg cdL g 21 of CPG [5] and the 30 mg GIgG g 21 of CPG, [6] but higher than the 1 mg anti-IgG-FITC g 21 of CPG. [4] In the analysis of the above results and, although the differences of the supports, it is necessary to consider that in both cases the immobilized Spherical vs. Granular Immobilization Support 343 protein values present in the literature were higher than the above values of the TRISO(-NCS) 47.8 nm; the incubated protein concentration was also higher than those used in the assay (50 mg AP g 21 of support), as can be observed in Table 1.…”

“…The PDITC procedure: [4,5,13,14] 0.5 mL of the solvent DMF containing 0.5% (v/v) TEA (DMF-TEA) with 0.154 g of PDITC were combined Spherical vs. Granular Immobilization Support 335 with 0.4 g of each four types of TRISO(-NH 2 ) following the proportion of approximately 2 mM of PDITC per g of support in the DMF-TEA. The mixture was degassed and incubated for 1.5 h with gentle stirring at room temperature (20 -258C).…”

“…The immobilization of GIgG in the isothiocyanate supports TRISO(-NCS) 47.8 nm and CPG(-NCS) was performed according to a procedure described by Rosa et al [5] 0.0066 g of each support was weighed into a roundbottomed Eppendorf tube and washed twice with 44 mL (approximately 2 volumes of support) of distilled water, withdrawing the washing water carefully with a micropipette. The supports were then washed once with 44 mL of carbonate buffer and the buffer was carefully withdrawn with a micropipette.…”

Biosensors for environmental pollutants and food contaminants

“…For example, Hart et al investigated the detection of sulfur dioxide in gas streams using screen-printed electrodes [80], Rosa et al developed an optical biosensor based on nitrite reductase for monitoring purposes with a limit of detection of only 0.93 µM, which is below the admissible concentration of 2.2 µM imposed by European Community norms [81]. An unusual approach was described by Sarkar, in which proteases are used for the detection of dust particles [82].…”

A highly selective optical sensor for catalytic determination of ultra-trace amounts of nitrite in water and foods based on brilliant cresyl blue as a sensing reagent

“…or chemical (covalent bond) methods [20]. Optodes are used based on different analytical techniques such as absorbance [21], fluorescence [22], or reflectance [18,19] the best of the authors' knowledge, only a few studies have been reported on the determination of nitrite based on optical sensors [23][24][25][26][27] using spectrophotometric measurement [23][24][25][26] and the quenching effect on chemiluminescence of CdSe [27]. Despite their advantages, all the optodes, however, suffer from the interference of oxalate and Fe(III) and from their inability to measure nitrite at concentrations below 5 ng mL −1 .…”