FUNCTIONS AVAILABLE WITH PROBE

AVG(x) running average of x over the range of the x-axis variable  

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Nearly all these techniques involve interrogation of the surface with a particle probe. The function of the probe is to excite surface atoms into states giving rise to emission of one or more of a variety of secondary particles such as electrons, photons, positive and secondary ions, and neutrals. Because the primary particles used in the probing beam can also be electrons or photons, or ions or neutrals, many separate techniques are possible, each based on a different primary-secondary particle combination. Most of these possibilities have now been established, but in fact not all the resulting techniques are of general application, some because of the restricted or specialized nature of the information obtained and others because of difficult experimental requirements. In this publication, therefore, most space is devoted to those surface analytical techniques that are widely applied and readily available commercially, whereas much briefer descriptions are given of the many others the use of which is less common but which - in appropriate circumstances, particularly in basic research - can provide vital information. 

In the literature, fluorescence spectroscopy in OFD has been limited to the use of ultraviolet (UV) or visible dyes as molecular probes.(1) The most common fluorescent dye used in OFD is fluorescein and its derivatives/21 23) Fluorescein possesses a good fluorescence quantum yield and is commercially available with an isothiocyanate functionality for linking to the polymeric support/24-26 Additionally, selective laser excitation can be performed because the absorbance maximum of fluorescein coincides with the 499-nm laser line emitted from an argon laser. Unfortunately, argon lasers are costly and bulky, thus limiting the practicality of their use. Similar difficulties exist with other popular commercial dyes. 

When the reaction product(s) is obtained in pure form, modern instrumental methods of structure determination, rather than traditional wet methods, provide file fastest way to determine the functionality and connectivity present. Today s chemist has a large number of tools available with which to probe the structure of molecules, but for determining the structures of organic molecules the big three are nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy, and mass spectrometry (MS). The frequency of use of these techniques generally falls in the same order (NMR > IR > MS). 

The AFM FV measurements are carried out in contact mode using 11-mercapto-1-undecanol monolayer functionalized gold-coated probe tips (these functionalized probes are commercially available, see Appendix, or can be prepared according to the literature [10]). All measurements are performed in Milli-Q water using a liquid cell without O-ring (see Sect. 3.3 in Chap. 3). The use of very soft cantilevers with a nominal spring constant of 0.06 N/m is advisable. 

Details of our work are available in recent publications [12, 13], however briefly to here we show, SERS detection experiments conducted using nanoparticles functionalized with probes specific to DENV-2 and introducing (in separate experiments) DENV-2a and DENV-4a targets. Figure 8 shows the SERS spectra collected on-chip for (a) no target DNA... 

There several DO probes available. Some well-known branded fermenters, like New Brunswick, Bioflo series and the B. Braun Biotstat B fermenters are equipped with a DO meter. This unit has a 2 litre fermentation vessel equipped with DO meter and pH probe, antifoam sensor and level controllers for harvesting culture. The concentration of DO in the media is a function of temperature. The higher operating temperature would decrease the level of DO. A micro-sparger is used to provide sufficient small air bubbles. The air bubbles are stabilized in the media and the liquid phase is saturated with air. The availability of oxygen is major parameter to be considered in effective microbial cell growth rate. 

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