3.3 Biomimetic Photosensors

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Figure 3.7: A photo-luminescent rod-mimic that detects pyrrole [12]. (a) Luminescence of the rod;

(b) different concentrations of pyrrole result in different amount of luminescence; (c) luminescence and

pyrrole concentration are linearly related; (d) the luminescence at each concentration is constant over min-

utes.

In one case, columns are packed with a solid phase of molecularly-imprinted particles

(MIPs), whose imprints are specific for antibiotics [14]. A fluorescent analogue to each

antibiotic is synthesized. Then a known concentration of a fluorescently-labeled antibi-

otic will compete with the nonfluorescent antibiotic in binding to the specific, imprinted

sites of the column. To determine the amount of antibiotic in a sample, the fluorescence

of the solution exciting the column is measured. In this case, the sensing element is then

the imprinted site, the transduction is the competing molecule, and the analysis is per-

formed by fluorescent light.

In another example, the binding surface is polyacetylene combined with a lipid

monolayer [15]. The color of polyacetylene is based on the conjugation length of