Recent Developments in Rhodamine-Based Chemosensors: A Review of the Years 2018–2022

Abstract

Chemosensors based on traditional fluorescent dyes have always contributed to the development of chemical sensor areas. In this review, the rhodamine-based chemosensors’ improvements and applications from 2018 to 2022 are discussed, mainly focusing on cations (metal ions and H+), anions (CN−, F−, etc.), and small bio-functional molecules’ (thiols, amino acids, etc.) detection. Specifically, this review highlights the detection target, detection limit, detection solution system, detection mechanism, and performance of the rhodamine-based sensors. Although these rhodamine-based sensors are well developed, their repeatability and sensitivity still need significant improvement. This review is expected to bring new clues and bright ideas to researchers for further advances in rhodamine-based chemosensors in the future.

Dual color pH probes made from silica and polystyrene nanoparticles and their performance in cell studies

“…The interest in measuring pH in biological systems together with the general advantages offered by fluorescence methods such as relatively simple and inexpensive instrumentation 11,12 , minimal invasiveness, and suitability for the in situ online monitoring of local pH using, e.g., optical microscopy, and remote sensing 11,12 has triggered the development of pH-responsive organic fluorophores from different dye classes. This includes BODIPY and BF 2 -chelated tetraarylazadipyrromethene dyes [13][14][15][16][17][18] , as well as xanthene [19][20][21][22][23][24] , cyanine [25][26][27][28][29] , squaraine 23 , and naphthalimide fluorophores [30][31][32][33] , which exploit intramolecular photoinduced electron transfer (PET), intramolecular charge transfer (ICT), and fluorescence energy transfer processes for the signaling of pH. Optical parameters utilized for the determination and monitoring of pH are pH-induced changes in the spectral position and/or intensity of the dye's absorption and/or emission bands or fluorescence lifetime 31,[34][35][36][37] .…”

Structure–metal ion selectivity of rhodamine-based chemosensors

“…A few review articles are available [4][5][6][7] but most of them are quite outdated. Meanwhile, a great number of research articles have been published that report chemosensors that are able to detect one, two or more metal ion(s) by producing the same output signal.…”

Enhanced Photoluminescence of R6G Dyes from Metal Decorated Silicon Nanowires Fabricated through Metal Assisted Chemical Etching

“…However, it is important to note that the size, shape, and morphology of the structures have a significant effect on the optical properties and influence the wavelength and width of the SPP resonance band of the metal nanostructures [ 13 , 15 , 33 ]. Various dye molecules such as Rhodamine 6G (R6G) [ 34 ], and Crystal Violet on rough surfaces have been demonstrated to experience significant enhancement in the optical absorption, and emission spectra [ 35 ].…”