Activatable Chemiluminescent Molecular Probes for Bioimaging and Biosensing

Abstract

Chemiluminescence (CL) is a very promising method for applications in analytic chemistry and biological systems due to the elimination of the external light source, which could reduce autofluorescence interference and improve the signal‐to‐noise ratio (SNR) and tissue penetration depth. The fluorescent dyes, chemiluminescent initiator, and reaction temperature are three crucial factors that determine the chemiluminescence efficiency. Up to now, significant development of chemiluminescence probes has been reported for high‐performance imaging and sensing, including the systems based on luminol, imidazopyrazinone, peroxyoxalate, and Schaap's dioxetane. In this review, we give an overview of the current chemiluminescence probes and their bioimaging and biosensing applications. We also provide perspectives on designing chemiluminescent probes with good efficiency and longer emission wavelengths.

The Molecular Basis of Organic Chemiluminescence

“…The CL emission spectrum obtained in the different transformations is not related to the chemiexcitation mechanism but simply to the fluorescence spectrum of the reaction product formed in its excited singlet state or the excitation energy acceptor present in the system that receives the excitation energy from the initially formed excited product. In the peroxyoxalate reaction, the CL emission wavelength can be chosen almost at will by the choice of the emission spectrum of the activator used, which is chemiexcited by interaction with the high-energy intermediate formed in the reaction sequence [ 108 , 109 , 110 , 111 , 112 ].…”

Chemiluminescent Conjugated Polymer Nanoparticles for Deep-Tissue Inflammation Imaging and Photodynamic Therapy of Cancer

“…However, due to the limited penetration depth and the autofluorescence of biological tissues, fluorescence imaging encounters a lot of difficulties in deep tissues. Although several red and near-infrared (NIR) fluorescence probes have been commonly explored to enhance the penetration depth, the need for external excitation light source still limits the application of some fluorescence agents in complex deep tissues. − Photodynamic therapy (PDT), as a promising cancer treatment strategy, contains three key elements: photosensitizer, light source, and molecular oxygen . Similar to fluorescence imaging, the requirement of an external excitation light source and the limited penetration depth of light retard PDT for diseases in deep tissues.…”

Emission Wavelength-Tunable Bicyclic Dioxetane Chemiluminescent Probes for Precise In Vitro and In Vivo Imaging

“…In the 1980s, the Schaap group reported that certain analytes could specifically trigger 1,2-dioxetanes bearing a phenol functional group to emit strong chemiluminescence, highlighting the great potential as a versatile chemiluminescent platform for detecting a range of biological analytes of interest (Figure b). − Since 2015, the Lippert, Shabat, and Pu groups have made many useful modifications to Schaap’s dioxetanes, significantly augmenting the biological applications of dioxetane-type CPs. − The introduction of a fluorophore moiety onto the phenol moiety of the adamantyl dioxetane core structure resulted in the first dioxetane-based bioimaging without the requirement of additives . To further improve the properties of these probes under physiological conditions, the Shabat group incorporated an electron-withdrawing methyl acrylate group into the phenol moiety, leading to a significant increase in red-shifted emission wavelengths and chemiluminescence intensity .…”