Detection sensor sensitivity

In recent years, rapid advancements in photonic technologies have significantly enhanced the photonic bio/chemical sensor performance, especially in the areas of (1) interaction between the light and analyte, (2) device miniaturization and multiplexing, and (3) fluidic design and integration. This has led to drastic improvements in sensor sensitivity, enhanced detection limit, advanced fluidic handling capability, lower sample consumption, faster detection time, and lower overall detection cost per measurement. 

Transport detectors are a unique type of solute property detector in that the signal from the sensor is entirely independent of the solvent that is used as the mobile phase. Various forms of transport detectors have been commercially available over the years past but, due to certain deficiencies in the early models, they did not become popular and (to the author s knowledge) none are currently being manufactured. Nevertheless, the transport detector has the potential qualities that are inherent in the ideal detector, i.e. universal detection, high sensitivity,... 

Dissolved oxygen sensors, pH electrodes, or specific ion electrodes can be fitted, and a fluorometer for petroleum oils was developed from the chlorophyll sensor (sensitivity, 1 /xg of naphthalene/L). A solid-state bioluminescence sensor was developed (18) with a minimum detection of 5 x 10 W equivalent to about 10 quanta/s at 480 nm, sufficiently low for the detection of a single dinoflagellate flash (19). 

As follows from (3), sensor sensitivity is proportional to the sensor length L. In turn, as follows from (2), the maximal sensor length is limited by the absorption loss of a fiber. Defining / det(2) to be the power detection limit at which changes in the light intensity can still be detected reliably, the maximal sensor length allowed by the power detection limit can be calculated from (2) as ... 

Another important area where gold-thiol monolayers might find promising applications is gas- and biosensing. Simple sensors sensitive to certain types of compounds, based on such detection methods as surface plasmon resonance or surface acoustic wave, have been described454,455,531-533. This type of device is usually made of a gold plate coated with a functionalized monolayer. The terminal functional group of such a monolayer is responsible for selective interactions with the analyte, and adsorption of the latter is then detected by the appropriate method. 

SPR sensors directly measure refractive index. In conjunction with appropriate biorecognition elements, they can be used as affinity biosensors allowing detection of the capture of analyte molecules by biorecognition elements immobibzed on the sensor surface. The abihty of SPR sensors to perform measurements is described by the performance characteristics, of which the most important are the sensitivity, resolution, accuracy, reproducibihty, and hmit of detection. The sensitivity and resolution are primarily determined by the properties of the optical system of the SPR sensor and can be linked to specific design parameters. 

Specific Sensor analyte system designation Comments Detection matrix Sensitivity Assay format Reference... 

Type of Sensor Principle Detected Explosive Sensitivity Application Time... 

Various kinds of metal oxide semiconductors have been investigated since SnOj was found to be able to detect NO,( sensitively by Chang[44,45]. At the beginning of the researches and developments, SnO was focused as an active material, but recently other metal oxides have been studied intensively rather than SnOg because of the problems of SnOj such as a lack of sensitivity and a drift of sensor signals. 

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