Glasses surface charging problems

Depth profiling glasses with ion beam techniques is also difficult due to surface charging problems. Pulsed ion beams in ToF-SIMS with relatively long interpulse periods have been used successfully, however. ARXPS can be used to study variation in composition and chemical states over the outer 10 nm. Nuclear techniques, such as PIXE, NRA, RBS and ERDA, are particularly useful in studying the composition of deeper lying altered layers to depths of pm. The latter techniques generally have depth resolutions of the order of 10 nm which is sufficient in most cases [93]. 

As a supplement for widely used glass electrodes, ISFET sensors provide some unique features. One of them is the capability of dry storage, which helps to avoid the problem of shelf-life and the hydration requirement time for glass electrodes. Fast response is another feature of an ISFET pH sensor. In a comparison study of commercial pH sensors reported by Smit et al. [84], the ISFET sensor showed about a ten times faster response than that of glass electrodes, and a response similar to that of an iridium oxide-based electrode [100, 104], This fast response time of ISFET sensors was attributed to its sensing mechanism, which is based on the electrostatic interaction of H+ ions with surface charge at the gate surface [66]. 

Excessive or unevenly applied subbing agent on poly-L-lysine, charged, or silanized slides. Some IHC reagents may bind to these products, resulting in a light stain over the entire slide surface. Some slides may be unevenly coated, and will exhibit the above problems on only a portion of the tissue or glass. 115-121... 

A variety of surfaces such as metals, plastics, and glass can retain proteins during a separation process. In CE, a problem is manifested in the adsorption of proteins by fused silica capillaries (see Section IV). This problem is attributed to the adsorption of positively charged sites of proteins on negatively charged sites (silanol groups) on the capillary wall—a process that leads to band broadening and a much lower number of theoretical plates than would be expected on the basis of theory. 

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