The Application Of Electrochemiluminescence For The Detection Of Endocrine Disruptors In Water Environment

Electrochemical luminescence(ECL),as a new detection technique,is an important part of the field of electrochemical analysis and detection.This method has many advantages,such as high sensitivity,wide linear range,low detection limit and simple operation.In recent years,with its unique advantages,ECL technology has aroused great interest in research and has been widely used in environmental,food and medical fields.In this paper,a series of ECL sensors were constructed for endocrine disruptors assay in water environment.The specific studies are as follows:1.Highly sensitive and selective bisphenol A assay using solid-state electrochemiluminescence aptasensing platform based on Ru(bpy)32+encapsulated MIL-125Ultrasensitive and selective detection of bisphenol A(BPA)was achieved by the proposed solid state electrochemiluminescence(ECL)aptasensor here.Ti-based MOFs(MIL-125,MIL stands for Materials of Institute Lavoisier)with porous structure and large specific surface area,which used as carrier for Ru(bpy)32+was simply prepared by a hydrothermal synthesis method.The prepared Ru(bpy)32+encapsulated MIL-125(Ru(bpy)32+-MIL-125)was dropped on a glass carbon electrode(GCE)and worked as work electrode.After that,the thiol-based aptamer of BPA was steadily modified to work electrode by Ti-S bond.Resulted from the specific binding affinity between aptamer and BPA,a selective ECL aptasensor for BPA was thus developed.The ECL aptasensor based on Ru(bpy)32+-MIL-125 has a good ECL response toward detecting BPA.Under optimal conditions,the aptasensor could detect BPA in a wide linear range from 1.0×10-12 mol/L to 1.0×10-6 mol/L with an excellent detection limit of 6.1×10-13 mol/L(S/N=3).Furthermore,the proposed ECL aptasensor could selectively detect BPA in a mixture solution containing BPA interference compounds.We believe the proposed ECL aptasensor in this work has a wide application potential in the field of environmental monitoring and food safety.2.NH2-MIL-125 as a novel catalyst in PTCA-K2S2O8 system for enhancing electrochemiluminescence behavior of PTCA and its application in detection of diethylstilbestrolIn this work,3,4,9,10-perylenetetracar-boxylic acid(PTCA)as luminophor was decorated on the surface of metal-organic framework(NH2-MIL-125)directly.NH2-MIL-125 exhibited large specific surface area and excellent electrical conductivity which can immobilize large amounts of PTCA to improve the ECL efficiency.Moreover,NH2-MIL-125 was used as a novel co-reaction accelerator in PTCA-K2S2O8 system,which can react with the co-reactant(K2S2O8)to produce more SO41-.In addition,we introduced the amino-aptamer of diethylstilbestrol,resulted from the specific binding affinity between aptamer and diethylstilbestrol(DES),a selective ECL aptasensor for DES was thus developed here.Under the optimal condition,a wide detection range from 1.0×10-15 mol/L to 1.0×10-6 mol/L and a low detection limit of 2.8×10-16 mol/L(S/N=3)were obtained.More importantly,the residual DES in pond water was monitored by the developed aptasensor,which exhibited superior determination and potential application in real samples.3.An "off-on" electrochemiluminescence aptasensor for microcystin-LR assay based on the resonance energy transfer from PTCA/NH2-MIL-125(Ti)to gold nanoparticlesIn this work,a novel "off-on" ECL aptasensor based on ECL resonance energy transfer(RET)system from 3,4,9,10-perylenetetracar-boxylic acid/the metal-organic frameworks NH2-MIL-125(Ti)(PTCA/NH2-MIL-125)to Au nanoparticles(Au NPs)was put forward for microcystin-LR(MC-LR)assay.The ECL emission spectral of PTCA/NH2-MIL-125 shows excellent spectral overlap with the UV-vis absorption spectrum of Au NPs.A linear response range from 1.0×10-14 mol/L to 1.0×10-7 mol/L was obtained,and the low detection limit was calculated as 3.6×10-15 mol/L under optimal conditions at the potential of-1.6 V(S/N=3).Besides,the prepared ECL-RET MC-LR aptasensor exhibited high specificity,good selectivity and stability.4.Determination of acetamiprid using electrochemiluminescent aptasensor modified by MoS2QDs-PATP-PTCA and NH2-UiO-66In this work,a novel aptasensor was fabricated based on the resonance energy transform(RET)system from MoS2QDs-PATP/PTCA(donor)to NH2-UiO-66(acceptor).The electrochemiluminescence(ECL)signal of PTCA was greatly amplified due to the decoration of MoS2QDs-PATP,and the NH2-UiO-66 was utilized to label the signal probe DNA(pDNA),which would hybridize with the exposed aptamer anchored on the surface of MoS2QDs-PATP-PTCA.With the target acetamiprid,the specific binding of acetamiprid to aptamer would cause the connection between the donor and the acceptor to be interrupted and produced an "on" ECL signal.Thus,an "off-on" ECL sensing platform for sensitive and selective acetamiprid assay was designed.Under the optimal condition,the ECL aptasensor was found to be linearly related to the logarithm of the acetamiprid concentration ranging from 1.0×10-16 mol/L to 1.0×10-7 mol/L with a detection limit of 6.4×10-17 mol/L.More importantly,the recovery rate of the ECL aptasensor was calculated to be 98.7～106%with the RSD lower than 5.1%for the residual acetamiprid assay in real food samples,which indicated that the aptasensor has great practical applications.5.A novel electrochemiluminescence sensor based on the resonance energy transfer from MoS2QDs-g-C3N4 to NH2-SiO2-PTCA for glutathione assayIn this work,a solid-state electrochemiluminescence(ECL)sensor based on a new resonance energy transfer(RET)system was proposed using MoS2QDs-g-C3N4 as donor and NH2-SiO2-PTCA as acceptor.Herein,MoS2QDs could significantly facilitate the stability and efficiency of the ECL of g-C3N4.The PTCA provided a large platform to anchor NH2-SiO2 nanoparticles.The prepared MoS2QDs-g-C3N4 exhibited good spectral overlap with the UV-vis absorption spectrum of NH2-SiO2-PTCA.Based on this,we designed an "off-on" ECL sensing strategy for sensitive and selective detection of glutathione(GSH).Under the best conditions,the linear range of the sensor for GSH detection was from 1.0×10-9 mol/L to 1.0×10-4 mol/L with a detection limit of 6.3×10-10 mol/L(S/N=3).More importantly,the GSH in commercial samples can be detected by the proposed sensor,which indicated superior detection capabilities and potential application value in real water samples.6.Plasmon-Enhanced Electrochemiluminescence of the 1D-2D PTCA-Co3(P04)2 based on Au NPs for diclofenac assayThe combination of localized surface plasmon resonance(LSPR)and electrochemiluminescence(ECL)can be an effective way to amplify the signal intensity.In this work,an ECL aptasensor with PTCA-CoP as ECL emitter and Au NPs as plasma source was proposed for diclofenac assay.The special 1D-2D structure of prepared PTCA-CoP leads to good stability and excellent ECL performance.The diclofenac aptamer here acts as a bridge to link the PTCA-CoP and Au NPs,thus the ECL performance of PTCA-CoP was greatly improved due to the plasma effect of Au NPs.Besides,it was found that the ECL performance of the aptasensor was negatively correlated with the concentration of diclofenac and a low detection limit of 7.2×10-14 mol/L(S/N=3)was obtained.More importantly,the aptasensor was proved to be suitable for the detection of diclofenac in real water samples,suggesting it has great practicability.