A Ratiometric Fiber Optic Sensor Based on CdTe QDs Functionalized with Glutathione and Mercaptopropionic Acid for On-Site Monitoring of Antibiotic Ciprofloxacin in Aquaculture Water

Abstract

A ratiometric fluorescence fiber-optical sensor system (RFFS) merging a Y-type optical fiber spectrometer and CdTe QDs composite functionalized with glutathione and mercaptopropionic acid (GMPA@CdTe-QDs) for highly selective and on-site detection of ciprofloxacin (CIP) in environmental water samples was designed. Our preliminary results suggested that the red fluorescence of the synthesized GMPA@CdTe-QDs was effectively quenched by CIP. Based on this, the RFFS/GMPA@CdTe-QDs system was successfully fabricated and used for highly selective and rapid detection of CIP on site in the concentration range from 0 to 45 μM with the detection limit of 0.90 μM. The established method exhibited good interference resistance to the analogues of CIP and provided a great potential platform for real-time detection of CIP residues in environmental water. In addition, the fluorescence quenching mechanism of GMPA@CdTe-QDs by CIP was also investigated by means of temperature effect, fluorescence lifetime, ultraviolet (UV) visible absorption, and fluorescent spectra. Our results suggested clearly that the red fluorescence of GMPA@CdTe-QDs was quenched by CIP via the photoinduced electron-transfer (PET) mode.

Highly Coupled Seven-Core Fiber for Ratiometric Anti-Phase Sensing

“…Therefore, fiber optic sensors have been developed to operate in harsh environments [ 19 , 20 ] and have shown reliability in measuring optical and mechanical variables such as refractive index [ 21 , 22 ], curvature [ 23 , 24 ], surface tension [ 25 , 26 ], and temperature [ 27 , 28 ]. Ratiometric sensing has been implemented in optical fibers to measure oxygen concentration [ 29 , 30 ], pH [ 31 , 32 , 33 ], and antibiotics [ 34 ]. In general, ratiometric fiber sensors use engineered fluorophores attached to optical fibers, generating a convenient optical probe for in-site measurement.…”

Ciprofloxacin Removal from Aqueous Media Using Floating Treatment Wetlands Supported by Immobilized Bacteria

“…Ciprofloxacin (CIP, C 17 H 18 FN 3 O 3 ), a fluoroquinolone antibiotic with fractions of piperazine, is extensively used to prevent gastrointestinal infections, urinary tract infections, and lung and skin infections for both humans and animals [7][8][9][10]. It has a broad-spectrum antibacterial activity that inhibits the synthesis of essential bacterial enzymes such as topoisomerase IV and DNA gyrase [11].…”

Improving the Sensitivity of Nanofibrous Membrane-Based ELISA for On-Site Antibiotics Detection

“…In developing highly selective and sensitive sensors for on-site detection of toxic chemicals, ELISA on nanofibrous membrane sensors was prepared with demonstrated ability and capacity of rapid, selective, naked-eye, and on-site detection. − A combination of sensitivity and selectivity of ELISA assay with ultrahigh specific surface area and porous structures of nanofibrous membranes was considered the best pathway to develop such unique personal use sensors. The specific surfaces area of a nanofibrous membrane should be at least three magnitudes (1000 times) higher than that of the conventional ELISA plates.…”