Near-Infrared Fluorescent Immunoassays: A Novel Approach to Environmental Analysis

Abstract

The near-infrared (NIR) region of spectrum provides many advantages over conventional UV--visible region and is particularly useful when background interference is the primary concern. Many NIR fluorophores have high molar absorptivities and fluorescence quantum yields. The use of laser diodes for excitation and photodiodes for detection makes the NIR fluorophores an ideal choice as tracers for various applications. NIR fluorescence immunoassays (NIRFIAs) for disease-related antigens have been developed and optimized in our laboratory during the past few years. NIRFIA can be used in both sandwich and competitive formats. We have successfully adapted the NIRFIA as both a microtiter plate assay and a fiber optic probe. This paper is focussed on the environmental analytical applications of this novel technique. Physical properties of ideal NIR labels and engineering problems of devising remote sensors are discussed. Conventionalimmunoassays have been recognized as a powerful tool in the analysis of minor components in a complex media.The use of laser induced fluorescence in the development of immunoassays has been reviewed (1). The limitations in using conventional lasers as an excitation source are size, high price, and maintenance costs. Recent advances in semiconductor laser technology have made the use of these lasers as an excitation source more

Mono‐ and Di(dimethylamino)styryl‐Substituted Borondipyrromethene and Borondiindomethene Dyes with Intense Near‐Infrared Fluorescence

“…The development of functional dyes that absorb and emit in the red visible or near‐infrared (NIR) region of the optical spectrum has received increasing attention in the last decade. Although there has been considerable interest in NIR dyes since the early/middle of the last century,1 from advances in photography2 through attempts at optical data storage3 and lasing4 to novel low‐noise detection techniques in various analytical methods such as electrophoresis5 or immunoassays,6 research in this area showed a real boost only with the technological advances in NIR imaging instrumentation. Thus, nowadays NIR dyes play a prominent role in many fields of medicinal chemistry and biotechnology, ranging from tomography7 through endoscopic imaging8 and tumor diagnostics9 to drug discovery10 and nucleic acid detection 11.…”

Ultrasensitive Detection of Closely Related Angiotensin I Peptides Using Capillary Electrophoresis with Near-Infrared Laser-Induced Fluorescence Detection

“…The addition of sulfonate groups to the dye structures greatly improves their solubility, and the addition of reactive groups such as isothiocyanate functionalities makes them suitable for use as covalent labels . Reported uses of NIR dyes for analytical applications include enzymatic assays, hydrophobicity, metal ion and pH probes, immunoassay applications, and as labels for DNA sequencing studies. − …”