A photoelectrochemical immunosensor for tris(2,3-dibromopropyl) isocyanurate detection with a multiple hybrid CdTe/Au-TiO2 nanotube arrays.

In this paper, tris(2,3-dibromopropyl) isocyanurate (TBC) is for the first time as far as we know determined by ultrasensitive photoelectrochemical (PEC) immunoassay using an antibody-modified ternary hybrid CdTe/Au-TiO2 nanotube arrays (NTAs) photoelectrode, developed by the pulse electrodeposition technique. The as-prepared hybrid shows enhanced photon absorption and photocurrent response, which subsequently increased the photoelectrical conversion efficiency in the visible region. TBC-antibody (Ab) was developed in rabbits as a result of immunization with the BSA-TBC conjugate and covalently cross-linked onto the CdTe/Au-TiO2 NTAs. Since the photocurrent is highly dependent on the TiO2 surface properties, the specific interaction between TBC and the antibody results in a sensitive change in the photocurrent, which displayed a linear range of 5.0 × 10(-11) to 5.0 × 10(-5) M and a low detection limit of 5.0 × 10(-11) M for TBC determination. This proposed strategy highlights the application of TiO2 nanotube in visible-light-activated photoelectrochemical biosensing, which could largely reduce the destructive effect of UV light on biomolecules.

Electrogenerated chemiluminescence detection of trace level pentachlorophenol using carbon quantum dots.

Pentachlorophenol (PCP) is an environmental pollutant of serious concern due to its high toxicity and long persistence property. Fast and sensitive detection of PCP is therefore of great interest. In this work, carbon quantum dots (QDs) are synthesized by hydrothermal reaction, and characterized by fluorescence spectrophotometer, fourier transform infrared (FT-IR) spectroscopy, UV/vis/NIR spectrophotometer and scanning electron microscopy (SEM). The carbon QDs show stable and intensive electrogenerated chemiluminescence (ECL) in the presence of the coreactant S2O8(2-). Under the scanning potential of -1.2 to 0.5 V, PCP reacts with the excited C˙(-), resulting in a decrease in ECL. The detection of trace level PCP is therefore achieved using the carbon QDs and Pt working electrode. Parameters that may affect the ECL intensity including the pH of solution, ionic strength, concentrations of coreactant and carbon QDs are optimized. Under the optimal conditions, a detection limit of 1.3 × 10(-12) g L(-1) is achieved with a linear range of 10 pg L(-1)∼1.0 µg L(-1).