Development of Functional Fluorescent Molecular Probes for the Detection of Biological Substances

Abstract

This review is confined to sensors that use fluorescence to transmit biochemical information. Fluorescence is, by far, the most frequently exploited phenomenon for chemical sensors and biosensors. Parameters that define the application of such sensors include intensity, decay time, anisotropy, quenching efficiency, and luminescence energy transfer. To achieve selective (bio)molecular recognition based on these fluorescence phenomena, various fluorescent elements such as small organic molecules, enzymes, antibodies, and oligonucleotides have been designed and synthesized over the past decades. This review describes the immense variety of fluorescent probes that have been designed for the recognitions of ions, small and large molecules, and their biological applications in terms of intracellular fluorescent imaging techniques.

Nanostructured Organic/Hybrid Materials and Components in Miniaturized Optical and Chemical Sensors

“…Then, metallic based plasmonic systems offer the most suitable platform [89]. This is true even for fluorescence, provided that a thin dielectric layer is inserted between the metal and the dye to avoid fluorescence quenching [90,91]. Actually, fluorescent-based methods are, in general, the most sensitive tools used for detection of small quantities of substances in different matrices.…”

Vitamin B6 Cofactor‐Conjugated Polyethyleneimine‐Passivated Silver Nanoclusters for Fluorescent Sensing of Zn2+ and Cd2+ Using Chemically Modified Cellulose Strips

“…[5] Considering the biological applications, the designing of fluorescent chemosensors need consideration of several requirements: the probe should display (1) efficient excitation with most laser-based instrumentation; (2) limited interference from sample auto-fluorescence; (3) limited cellular photodamage and scatter; (4) a high molar extinction coefficient and quantum yield, which may guarantee the use of lower dye concentrations and prevent toxicity in the living cell; and (5) presence of highly selective functional groups, which recognize the target chemical substance. [6] Looking forward to these positive aspects, the fluorescent metal nanoclusters (NCs) such as AuNCs, AgNCs, and their alloy NCs have attracted more and more attention in the fields of chemical sensing, molecular labelling, biological imaging, and catalysis due to one pot 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 green chemical synthesis, ultrafine size, size-dependent emission, low toxicity, anti-photo bleaching, higher PL quantum yield, large stokes shift, superior catalytic activity, high solubility, biocompatibility and high stability in ambient conditions. [7] As a novel type of fluorescent nanoprobe owing to the powerful antibacterial ability, silver nanoclusters have been extensively used to construct sensors for the detection of metal ions.…”

Distinct Interfacial Fluorescence in Oil‐in‐Water Emulsions via Exciton Migration of Conjugated Polymers

“…P1 is moderately water soluble and we observe the stable oil-in-water emulsions with the strongly increased red fluorescence at the oil-water interface (vide infra). We synthesize P1 via Sonogashira cross-couplings with M1 (diyne) and M2 (diiodide) in the presence of Pd(PPh 3 ) 4 , CuI, triethylamine, and tetrahydrofuran as a solvent (Figure 2a and detailed synthetic procedures in the Supporting Information). The perylene with a terminal acetylene was added in situ to perform the endcapping reaction of the polymer, providing a unimodal distribution of the polymers ( Figure S2, Supporting Information) with the molecular weight of 9.5 kDa and the polydispersity of 1.36.…”

“…[2,3] Various natural and synthetic fluorescent markers have been reported, and the emissions range from ultraviolet to near infrared with strong brightness resulting from high extinction coefficients and quantum yields. [2,4] Which specific phases are stained is determined by the chemical structures of dyes. For example, hydrophilic dyes partition to aqueous phases, lipophilic dyes assemble in lipophilic phases, and amphiphilic dyes can bind at hydrophobic-hydrophilic interfaces.…”