Nitrite sensor

Table 14. Optical response of a nitrite sensor layer.

Nitrite sensor Osmium-bipyridyl-modified quaternized poly(4-vinylpyri-dine) (PVP-Os) PSS or poly[aniline-co-N- (3-sulfopropyl)aniline (PAPSH) [206]... 

Figure 9. Schematic diagram of the nitrite sensor system. l.Air(28(Mj/ min) 2. Pump 3. Buffer (pH 2.0) 4. Sample solution> 5- Peristaltic pump 6. Pump 7. Valve 8. Incubator (30 C) 9. Microbial electrode 10. Waste 11. Amplifier 12. Recorder 13. Electrolyte (30% sodium hydroxide) 14. Teflon membrane 15. Buffer (pH 2.0) containing HCh gas 16. Immobilized whole cells 17. Gas permeable membrane ...

Anion detection at microelectrodes has not been studied widely. Amongst the first was the work of de Beer et al. [ 111 ] who manufactured a nitrite sensor with a tip just a few microns in diameter, which could detect nitrite ions down to 1 pM. This proved to be suitable for profiling the concentrations of nitrite anion within biofilms less than 1-mm thick inside water treatment plants. Other workers have found that use of an interdigitated microelectrode array [ 112] allows measurement of iodide via monitoring of its redox peak down to sub-micromole levels, making it a suitable technique for analysing mineral water. Carbon nanotubes coated onto Pt microdiscs have been utilised to make a nitrite sensor [113,114] with detection levels of 0.1 pM. Sulphide has also been detected at nickel microdiscs (50 pm diameter) [115]. 

Li, X., Sun, C. and Zhou, F. (2006b), A novel nitrite sensor based on poly-l-naphthylamine doped by a ferrocenesulfonic-acid-modified electrode. J. Anal. Chem., 61(9) 896-901. 

Yang, W. W., Bai, Y., Li, Y. C. and Sun, C. Q. (2005a), Amperometric nitrite sensor based on hemoglobin/colloidal gold nanoparticles immobilized on a glassy carbon electrode by a titania sol-gel film. Anal. Bioanal. Chem., 382(1) 44-50. 

Nie et al. developed a PEDOT-RGO nitrite sensor having a linear response range, LOD, and response time of 0.3-600 pM, 1 X 10" pM, and 8 s, respectively [92]. Like with DA and AA, the electrochemical methods have an advantage over the traditional spectrophotometric, chromatographic and chemiluminescent... 

Cosnier, S., C. Gondran, R. Wessel, R-P. Montforts, and M. Wedel (2003). A poly (pyrrole-cobalt(II)deuteroporphyrin) electrode for the potentiometric determination of nitrite. Sensors 3, 213-222. 

Strehlitz, B. Gruendig, B. Schumacher, W. Kroneck, P. M. H. Kotte, H. A nitrite sensor based on a highly sensitive nitrite reductase mediator-coupled amperometric detection. AnaZ. Chem. 1996,68, 807-816. 

The variety of measurable substrates has been expanded by applying enzymes or bacteria as catalysts for the formation or consumption of redox-active compounds in the sensor. Glucose oxidase has been used for glucose sensors (Cronenberg et al. 1991), cultures of methane oxidizers in methane sensors (Damgaard and Revsbech 1997), and pure cultures of incomplete denitrifiers in nitrate and nitrite sensors (Larsen et al. 1997, 1996). 

Maduraiveeran, G., Manivasakan, P.. and Ramaraj, R. (2011) Silver nanoparticles embedded three dimensional silicate sol gel matrix modified electrode for nitrite sensor application. Int J. NanotechnoL,... 

Ye D, Luo L, Ding Y, Chen Q, Liu X (2011) A novel nitrite sensor based on graphene/polyp5UTole/chitosan nanocomposite modified glassy carbon electrode. Analyst 136 4563... 

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