| Chirality is a fundamental chemical property in nature.Most biological molecules(protein,polysaccharide,RNA,DNA et)are chiral molecule,and their different configurations may show different biological and physiologicaland metabolic activities.Therefore,developing analytical methods with low cost,simple,sensitivity and fast for chiral recognition has becoming an increasingly significant topic of research.Electrochemiluminescence technique,as an effectively analytical approach,is a new and powerful tool for chiral recognition.Carbon nanomaterials and metallic nanomaterials have been widely applicatied in construction of sensor due to their large surface area,excellent conductivity and biocompatibility,and have the promise for chiral recognition of compounds via electrochemiluminescence.The key step for construction of the chiral sensing platforms is the immobilization of the chiral selectors,which always can be well obtained by combination with nanomaterials.The studies based on founctional carbon nanomaterials and metallic nanomaterials investigated the discrimination of chiral drugs or amino acids enantiomers.The main resrearch work includes three fractions as follows:1.A new electrochemiluminescence(ECL)interface has been constructed based on hemoglobin(Hb)and graphite-like carbon nitride nanosheets composite(Au-g-C3N4 NHs),and characterized by transmission electron microscope(TEM),ultraviolet–visible spectroscopy(UV-Vis)and electrochemical impedance spectroscopy(EIS).The advantages of Hb as chiral selector and Au-g-C3N4 NHs asluminophore were perfectly displayed in this novel interface.Then we used the chiral sensing platform forenantioselective recognition of penicillamine(Pen)enantiomers,and obtained different scanning tunneling microscope(AFM)images and ECL intensity after L-Pen and D-Pen adsorbed on Hb/Au-g-C3N4NHs/GCE,and a larger response was observed on D-Pen/Hb/Au-g-C3N4/GCE.This work with high selectivity,stability and reproducibility may open a new door based on ECL to discriminate Pen enantiomers.2.A sensitive and stereo-selective biosensor for L-glutamic acid(L-Glu)based on the electrochemiluminescence(ECL)of Ru(bpy)32+ has been designed by applying L-glutamic dehydrogenase(GLDH)for enzymatic generation of NADH in situ.The novel ECL Glu biosensor was prepared by immobilizing GLDH on the modified electrodes with Ru(bpy)32+-platinum nanoparticles(Ru-Pt NPs)and reduced graphene oxide-multiwall carbon nanotubes-Nafion(r GO-MWCNT-Nf).Fourier transform infrared spectroscopy(FT-IR),EIS,scanning electron microscopy(SEM)and cyclic voltammetry(CV)were employed to investigate the characteristics of different materials.In addition,the ECL technology was adopted to explore the interactions between the prepared Glu biosensor and L-and D-Glu.A remarkable difference of ECL intensity was observed when the proposed biosensor interacted with L-and D-Glu,respectively,and good responses were obtained from L-Glu.Therefore,it might provide a new perspective for the recognition and detection of L-Glu.3.An ultrasensitive and stereo-selective electrochemiluminescence(ECL)biosensor based on amplifying ECL signal of luminol was designed by immobilizing the D-amino acid oxidase(DAAO)to generate co-reactant in situ with reduced graphene oxide-hemin-cysteine(r GO-H-Cys)composite and gold-platinum nanowires(Au-Pt NWs)as catalysts for discrimination and detection of D-alanine(D-Ala).For this introduced biosensor,the r GO-H-Cys composite acts not only an amplification label to enhance the ECL response of luminol,but also an ideal nanocarrier to improve the electron transfer of the electrode surface.Further enhanced signal was obtained with the aid of Au-Pt NWs.Obvious difference of ECL signal was observed when the proposed biosensor interacted with alanine enantiomers(D-and L-Ala),and a higher signal was showed on D-Ala.This work implies the possibility for the determination of D-Ala in food industry. |
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