Fluorescent sensors glucose

The design of fluorescent sensors is of major importance because of the high demand in analytical chemistry, clinical biochemistry, medicine, the environment, etc. Numerous chemical and biochemical analytes can be detected by fluorescence methods cations (H+, Li+, Na+, K+, Ca2+, Mg2+, Zn2+, Pb2+, Al3+, Cd2+, etc.), anions (halide ions, citrates, carboxylates, phosphates, ATP, etc.), neutral molecules (sugars, e.g. glucose, etc.) and gases (O2, CO2, NO, etc.). There is already a wide choice of fluorescent molecular sensors for particular applications and many of them are commercially available. However, there is still a need for sensors with improved selectivity and minimum perturbation of the microenvironment to be probed. Moreover, there is the potential for progress in the development of fluorescent sensors for biochemical analytes (amino acids, coenzymes, carbohydrates, nucleosides, nucleotides, etc.). 

Appropriate combinations of boronic acid and fluorophores lead to a remarkable class of fluorescent sensors of saccharides (Shinkai et ah, 1997, 2000, 2001). The concept of PET (photoinduced electron transfer) sensors (see Section 10.2.2.5 and Figure 10.7) has been introduced successfully as follows a boronic acid moiety is combined intramolecularly with an aminomethylfluorophore consequently, PET from the amine to the fluorophore causes fluorescence quenching of the latter. In the presence of a bound saccharide, the interaction between boronic acid and amine is intensified, which inhibits the PET process (Figure 10.42). S-l is an outstanding example of a selective sensor for glucose based on this concept (see Box 10.4). 

The attachment of the dansyl unit to the secondary site of CD can also be accomplished by Hamasaki et al. [45], They examined the fluorescence properties of 33, 34,35, and 36, in which the dansyl moiety is attached to the secondary site (C3) of CD [43], Because the preparation of 3-deoxy-3-amino-CDs involves the inversion reaction at C3 that results in the conversion of one glucose member to an altrose residue, the modified CDs derived from 3-deoxy-3-amino-CDs have a distorted cavity with a decreased cavity space. As a result, (3-CD derivatives 33 and 34 cannot act as a fluorescence sensor, exhibiting fluorescence peaks at 580... 

Pickup JC, Hussain F, Evans ND, Rolinski OJ, Birch DJS. Fluorescence-based glucose sensors. Biosensors Bioelectronics 2005, 20, 2555-2565. 

Kamati VV, Gao X, Gao S, Yang W, Ni W, Sankar S, Wang B. A glucose-selective fluorescence sensor based on boronic acid-diol recognition. Bioorganic and Medicinal Chemistry Letters 2002, 12, 3373-3377. 

Phillips MD, James TD. Boronic acid based modular fluorescent sensors for glucose. Journal of Fluorescence 2004, 14, 549-559. 

Brown JQ, Srivastava R, Zhu H, McShane MJ. Enzymatic fluorescent microsphere glucose sensors evaluation of response under dynamic conditions. Diabetes Technology Therapeutics 2006, 8, 288-295. 

Ballerstadt R, Gowda A, McNichols R. Fluorescence resonance energy transfer-based near-infrared fluorescence sensor for glucose monitoring. Diabetes Technology Therapeutics 2004, 6, 191-200. 

Figure 11.2 Schematic of GOx-SWNT-based glucose sensor. Glucose oxidase immobilized on the nanotube surface catalyzes the oxidation of glucose. The reaction by-product, hydrogen peroxide, then reacts with the reaction mediator, potassium ferricyanide, adsorbed to the nanotube surface resulting in an increase in SWNT fluorescence. Adapted with permission from Ref. 28.

Sun, X. Y. Liu, B. Jiang, Y. B. An Extremely Sensitive Monoboronic Acid Based Fluorescent Sensor for Glucose. Anal. Chim. Acta 2004, 515, 285-290... 

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