Sense of Oxygen

So you do not wear unmatched socks or untied shoelaces. You comb your hair and, my word, you look exotic and even wear a little make up And you have the temerity to aspire to be a chemist. Good You appear not to be a careerist. I have no word for those who attempt to recruit me to assist them in mapping out every twist and turn of their lives. One can hardly be expected to serve as a role model (How I hate that expression ) when the lives of scientists are so serendipitous. I do assume you to be a scientist a young one, in the 

Letters to a Young Chemist, First Edition. Edited by Abhik Ghosh. 

Like you, I am told I grew up poor, though I cannot honestly claim I did. True, my childhood was spent on the island of Haiti crammed with my extended family into one or two small rooms of decrepit colonial houses. To see this, however, as the only notable aspect of my childhood would hardly do justice to the color and magic that pervaded my daily life, or the people and spirits who populated it. How might a passing tourist or Red Cross worker ever learn of the days spent inside, rapt by the adults embellishments on our many folk tales, while the furious hurricanes laid low our tall palms. How could one have been poor where material wealth was never a concern I grew to know that my relatives sacrificed daily to support 

Do apply yourself well to your studies of organic chemistry, and with this, physical chemistry and mathematics. One must master these subjects to understand biology in any way that is more than descriptive or superficial. One must respect biology too, if living organisms 

As far as we know, most living bacteria that sense O2 nowadays do so to gain information about their position rather than to avoid O2. Consider, for example, a jar of pure water that is bubbled with air at room temperature (23°C) and normal atmospheric pressure. After this water is completely equilibrated with air, it will have about 250 pM O2. This concentration of O2 can also be expected of anything that is completely equilibrated with air however, few living cells ever achieve such equilibration. In our own bodies, the surface layer of 

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Peterson et al.52 were the first to demonstrate sensing of oxygen in-vivo. The FOCS for measuring p02 consisted of two 250-pm strands of plastic... 

McDonagh C., MacCraith B.D., McEvoy A.K., Tailoring of Sol-Gel Films for Optical Sensing of Oxygen in Gas and Aqueous Phase, Anal. Chem. 1998 70 45-50. 

Borisov SM, Vasylevska AS, Krause C, Wolfbeis OS (2006) Composite luminescent material for dual sensing of oxygen and temperature. Adv Funct Mater 16 1536-1542... 

Figure 13.9. Phase angle sensing of oxygen using a LED-based oxygen sensor The bottle containing the sensor was removed and reinstalled between registrations A and B.

Potential applications of chemical sensors are diverse and numerous, and the environment where the sensor is used varies. Therefore, chemical sensor often requires to be tailor-made or semi-tailor-made to meet the needs in the special circumstance. For example, sensing of oxygen in an automobile exhaust or in water or in blood can be accomplished by using an electrochemical-based sensor. However, the selection of electrolyte and a diffusion-limited layer or protective membrane will be different in each case. Therefore, the platform chemical sensor technology is discussed in general. Special applications of a chemical sensor under a particular circumstance need to be addressed separately. 

Amao Y, 2003. Probes and polymers for optical sensing of oxygen, Microchim, Acta., 143, 1 12. 

Table 1.4 Comparison between the materials used so far for sensing of oxygen...

Amao Y (2003) Probes and polymers for optical sensing of oxygen. Mikrochim Acta 143 1-12 Amao Y, Nakamura N (2004) Optical CO2 sensor with the combination of colorimetric change of a-naphtholphthalein and internal reference fluorescent porphyrin dye. Sens Actuators B 100 347-351 Ando M, Kobayashi T, Haruta M (1994) Enhancement in the optical CO sensitivity of NiO film by the deposition of ultrafine gold particles. J Chem Soc Faraday Trans 90 1011-1013 Ando M, Kobayashi T, Haruta M (1995) Optical CO detection by use of CuO/Au composite films. Sens Actuators B 24-25 851-853... 

McDonagh C, MacCraith BD, McEvoy AK (1998) Tailoring of sol-gel films for optictil sensing of oxygen in gas and aqueous phase. Anal Chem 70 45-50... 

Achatz DE, Meier RJ, Fischer LH, Wolfbeis OS (2010) Luminescent sensing of oxygen using a quenchable probe along with upconverting nanoparticles. Angew Chtan Inti Ed 49 (in press). DOI 10.1002/anie.201004902... 

Fig. 2.19 Amperometric sensing of oxygen using (inset) micro-fabricated concentric ring disk...

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