Photoelectrochemical detection of pentachlorophenol with a Multiple Hybrid CdSe_xTe_1−x/TiO₂ Nanotube Structure-Based Label-Free Immunosensor

Abstract

Driven by the urgent demand of detecting trace amounts of pentachlorophenol (PCP) in contaminative water, a label-free immunosensor with ultra sensitivity and high selectivity was constructed based on a hybrid CdSe(x)Te(1-x) (0 ≤ x ≤ 1) nanocrystal (NCs)-modified TiO(2) nanotube (NT) arrays for the first time. The CdSe(x)Te(1-x) NCs were photoelectrodeposited on inner and outer space of the TiO(2) NTs, leading to high photoelectrical conversion efficiency in the visible region. PCP antibodies are covalently conjugated on the TiO(2) NTs due to the large surface area and good biocompatibility. Since the photocurrent is highly dependent on the TiO(2) surface properties, the specific interaction between PCP and the antibodies results in a sensitive change in the photocurrent, with a limit of detection (LOD) of 1 pM. High sensor-to-sensor reproducibility is achieved. The sensor was applied for the direct analysis of river water samples.

Determination of pentachlorophenol by anodic electrochemiluminescence of Ru(bpy)32+ based on nitrogen-doped graphene quantum dots as co-reactant

“…3,4 Moreover, the European Union and the US EPA have strictly limited the maximum admissible concentration (0.5 ppb and 1 ppb, respectively) of PCP in drinking water. 5,6 Thus, extensive efforts have been made towards the trace and ultratrace detection of PCP in the last decade. Various methods, including capillary electrophoresis, 7 gas chromatography (GC), 8 gas chromatography-mass spectrometry (GC-MS), 9 highperformance liquid chromatography (HPLC) 10 and uores-cence detection (FL) 11 have been explored for the measurement of PCP.…”

A signal-off sandwich photoelectrochemical immunosensor using TiO2 coupled with CdS as the photoactive matrix and copper (II) ion as inhibitor

“…Immunoassays have attracted interest with the expectation of obtaining prompt, accurate, and sensitive immunological response for food safety, environmental monitoring, and medical and clinical diagnosis (Liu et al, 2008;Tang et al, 2008). Some PEC analysis on the determination of anticholera toxin antibody (Haddour et al, 2006;Haddour et al, 2004), α-fetoprotein (Wang et al, 2009a), mouse immunoglobulin G (Wang et al, 2009b) and pentachlorophenol (Kang et al, 2010) have been reported in the past decade. In these investigations, the label-free method, which is based on the direct antibody-antigen affinity without markers, has been chosen for the purpose of saving time and cost (Haddour et al, 2006(Haddour et al, , 2004Kang et al, 2010;Wang et al, 2009aWang et al, , 2009b.…”

“…Some PEC analysis on the determination of anticholera toxin antibody (Haddour et al, 2006;Haddour et al, 2004), α-fetoprotein (Wang et al, 2009a), mouse immunoglobulin G (Wang et al, 2009b) and pentachlorophenol (Kang et al, 2010) have been reported in the past decade. In these investigations, the label-free method, which is based on the direct antibody-antigen affinity without markers, has been chosen for the purpose of saving time and cost (Haddour et al, 2006(Haddour et al, , 2004Kang et al, 2010;Wang et al, 2009aWang et al, , 2009b. Despite the good simplicity of the PEC label-free immunosensor, the sensitivity still needs to be improved due to the low capacity of analyte loading and inability for amplification .…”

Interfacial assembly of mesoporous nanopyramids as ultrasensitive cellular interfaces featuring efficient direct electrochemistry

“…[10][11][12][13] From these studies, molecular-semiconductor hetero-interfaces (such as protein-TiO 2 , 14,15 DNA-quantum dots, 16,17 organic molecule-silicon, 18 redox molecule-nanowires 19 and photoactive molecule-nanowires 20 ) have been applied to adjust photoelectrochemical (PEC) activities by enhancing the efficiency of PEC conversion. [21][22][23][24] In PEC-based bioanalysis (for example, DNA analysis, [25][26][27] immunoassays [28][29][30][31] and enzymatic sensing 32 ), PECenzymatic sensing has been the focus of considerable research because of the facile and inexpensive fabrication of appropriate interfaces and, more importantly, their high sensitivities and specificities. 33,34 In addition, third-generation PEC enzyme biosensors based on direct electrochemistry have been shown to be capable of direct electron transfer between their active sites and electrodes.…”