Electrochemical Chiral Recognition Research Articles

Electrochemical chiral sensor for recognition of amino acid enantiomers with cyclodextrin-based microporous organic networks

BackgroundChirality is a ubiquitous phenomenon in nature, but enantiomers exhibit different pharmacological activities and toxicological effects. Therefore, Chiral recognition plays a pivotal role in various fields such as life sciences, chemical synthesis, drug development, and materials science. The synthesis of novel chiral composites with well-defined loading capabilities and ordered structures holds significant potential for electrochemical chiral recognition applications. However, the design of selective and stable electrochemical chiral recognition materials remains a challenging task. ResultIn this work, we construct a simple and rapid electrochemical sensing platform for tryptophan (Trp) enantiomer recognition using cyclodextrin-modified microporous organic network as chiral recognition agent. CD-MON with chiral microenvironment was prepared by Sonogashira-Hagihara coupling reaction of the chiral molecule heptyl-6-iodo-6-deoxyβ-cyclodextrin and 1, 4-Diethynylbenzene. The adhesion of BSA makes CD-MON firmly fixed on the electrode surface, and as a chiral protein, it can improve the chiral recognition ability through synergistic effect. Chiral amino acids are in full contact with the chiral microenvironment during pore conduction of MON, and L-Trp is more stably bound to CD-MON/BSA due to steric hindrance, host-guest recognition and hydrogen bonding. Therefore, the electrochemical sensor can effectively identify tryptophan enantiomers (IL-Trp/ID-Trp = 2.02), and it exhibits a detection limit of 2.6 μM for L-Trp. UV–Vis spectroscopy confirmed the adsorption capacity of CD-MON towards tryptophan enantiomers in agreement with electrochemistry results. SignificanceThe prepared chiral sensor has excellent stability, reproducibility (RSD = 3.7%) and selectivity, realizes the quantitative detection of single isomer in tryptophan racemic and quantitative analysis in real samples with 94.0%–101.0% recovery. This work represents the first application of MON in chiral electrochemistry which expands the application scope of chiral sensors and holds great significance in separation science and electrochemical sensing.

L-Lysine-Functionalized Nickel–Zinc Bis(Dithiolene) Metal–Organic Framework for Electrochemical Chiral Recognition of Tryptophan Enantiomers

L<b>-Lysine-Functionalized Nickel–Zinc Bis(Dithiolene) Metal–Organic Framework for Electrochemical Chiral Recognition of Tryptophan Enantiomers</b>

Electrochemical chiral recognition of tryptophan enantiomers by using chiral polyaniline and β-CD-MOF.

Chiral detection of tryptophan (Trp) isomers is of vital importance and the introduction of efficient, stable and sensitive enantioselective recognition technology is in high demand in the fields of medicine, food and life science. Herein, a facile and sensitive electrochemical probe for the chiral recognition of Trp enantiomers by using chiral polyaniline (D-PANI) and β-CD-MOF is presented. The structure and electrochemical performance of the designed sensor (GCE/β-CD-MOF/D-PANI) were characterized via FT-IR, SEM, TEM, EIS, CV and DPV methods. Under the optimized conditions, the enantiomer selection coefficient (IL/ID) reached 2.26, and the detection limits for L- and D-Trp were calculated to be 6.67 and 16.1 μM, respectively. The higher DPV result for L-Trp was attributed to its higher affinity for the chiral selectors D-PANI and β-CD-MOF than that of D-Trp. Moreover, the proposed chiral sensing platform could be used for analyzing the percentage of D-Trp in enantiomer mixed solutions and human urine samples with satisfactory recoveries.

Construction of a Dual-Mode Biosensor with Ferrocene as Both a Signal Enhancer and a Signal Tracer for Electrochemiluminescent and Electrochemical Enantioselective Recognition.

We demonstrate for the first time the construction of a dual-mode biosensor for electrochemiluminescent (ECL) and electrochemical chiral recognition of l- and d-isomers of amino acids, with ferrocene (Fc) as both a signal enhancer and a signal tracer. With the dissolved oxygen as a coreactant, ZnIn2S4 acts as the ECL emitter to generate a weak cathodic ECL signal. Fc can enter into the β-cyclodextrin (β-CD) cavity on ZnIn2S4-modified electrode as a result of host-guest interaction. Since Fc can promote H2O and O2 to produce abundant reactive oxygen species (ROS) (e.g., O2·- and ·OH), the ECL signal of ZnIn2S4 can be further amplified with Fc as a coreaction accelerator. Meanwhile, Fc molecules on the β-CD/ZnIn2S4-modified electrode can be electrochemically oxidized to Fc+ to produce a remarkable oxidation peak current. When l-histidine (l-His) is present, the matching of the l-His configuration with the β-CD cavity leads to the entrance of more l-His into the cavity of β-CD than d-histidine (d-His), and the subsequent competence of l-His with Fc on the Fc/β-CD/ZnIn2S4-modified electrode induces the decrease in both Fc peak current and ZnIn2S4-induced ECL intensity. This dual-mode biosensor can efficiently discriminate l-His from d-His, and it can sensitively monitor l-His with a detection limit of 7.60 pM for ECL mode and 3.70 pM for electrochemical mode. Moreover, this dual-mode biosensor can selectively discriminate l-His from other l- and d-isomers (e.g., threonine, phenylalanine, and glutamic acid), with potential applications in the chiral recognition of nonelectroactive chiral compounds, bioanalysis, and disease diagnosis.

Electrochemical enantioselective recognition by defined chiral linkers in polysaccharides modified with carbon quantum dots

AbstractChirality exists everywhere in nature, so chiral recognition is also an extremely important field. This paper explores the recognition of amino acid configuration by an electrochemical chiral sensing platform constructed with carbon nanomaterials (carbon quantum dots (CQDs) as the substrate material) combined with chiral selectors (chitosan (CS)). CQDs/CS, which is bonded by intermolecular force, and CQDs‐CS, which is formed by covalent grafting through amidation, are selected as electrochemical chiral recognition materials, and a series of characterization methods are carried out to indicate the successful preparation of the materials, and then attached to the glass carbon electrode (GCE), forming a chiral sensing platform for amino acid enantiomers. The differential voltammetry (DPV) method was used to convert the chemical signal into electrical signal. The results showed that compared with CQDs/CS, CQDs‐CS had better enantiomer resolution to tryptophan (Trp), and the peak current ratio (IL/ID) was 2.28.

Chiral MOFs encapsulated by polymers with poly-metallic coordination as chiral biosensors.

Chiral materials have drawn the widespread attention for theirits chiral recognition ability. The design and synthesis of chiral material are of importance owing to the unpredictability in controlling chirality during the synthesis process. To circumvent problems, a chiral MOF (D-His-ZIF-8) was synthesized by ligand exchange of 2-methylimidazole (Hmim) on ZIF-8 by D-histidine (D-His), which can be treated as chiral host to distinguish amino acid enantiomers. The obtained D-His-ZIF-8 can provide chiral nanochannels for amino acid guests. Meanwhile, polynary transition-metal ion (Co2+ and Fe3+) coordinating with polydopamine (PDA) wrapped on the surface of D-His-ZIF-8 can increase theactive sites. The electrochemical chiral recognition behavior showed that D-His-ZIF-8@CoFe-PDA exhibited good recognition of the tryptophan enantiomer (L/D-Trp) (working potential of -0.2 V vs. Hg/HgCl2). The LOD and LOQ of L-Trp were 0.066 mM and 0.22 mM, respectively, while the LOD and LOQ of D-Trp were 0.15 mM and 0.50 mM, respectively. Finally, the usefulness of D-His-ZIF-8@CoFe-PDA/GCE was evaluated with a recovery of 94.4-103%. The analysisof real samples shows that D-His-ZIF-8@CoFe-PDA/GCE is a feasible sensing platform for the detection of L-Trp and D-Trp.

Design and Electrochemical Chiral Sensing of the Robust Sandwich Chiral Composite d-His-ZIF-8@Au@ZIF-8.

In the pursuit of chiral materials with significant chiral recognition effects and stability, various strategies have been explored, among which the integration of metal nanoparticles and chiral metal-organic frameworks (CMOFs) is highly promising. However, metal nanoparticles (MNPs)/CMOFs show high chiral properties but inferior stabilities due to the MNPs being easily detached from the outside layer under certain conditions. Sandwich MOFs@MNPs@CMOF chiral materials can overcome this dilemma because the sandwich structure can maximize the regulation of the chiral interface activity, while the controlled outer layer can stop the MNPs from falling off in the procedure of chiral recognition. Here, a novel sandwich chiral material (d-His-ZIF-8@Au@ZIF-8) was synthesized by a ligand-assisted strategy with a well-defined sandwich morphology and chiral recognition capabilities. The electrochemical chiral recognition showed that d-His-ZIF-8@Au@ZIF-8 was the most efficient for the enantiomer of phenylalanine (Phe). This experiment presents a novel perspective for the fabrication of a chiral electrochemical sensing platform based on a solid sandwich chiral nanocomposite.

Chiral template–induced porphyrin-based self-assembled materials for electrochemical chiral sensing

Chirality plays a key role in many fields of natural sciences as well as life sciences. Chiral materials are widely developed and used for electrochemical chiral recognition. In recent years, carbon quantum dots (CQDs) have been widely used as a novel carbon nanomaterial due to their excellent charge transfer properties, good biocompatibility, and low cost. The special structure of π-conjugated porphyrin attracts attention. Supramolecular self-assembly shows a way to construct chiral materials by self-assembling simple molecules into chiral composites. Herein, we demonstrate the self-assembly of achiral porphyrins induced by chiral carbon quantum dots assembled from L- and or D-tryptophan (L- and or D-Trp) with carbon quantum dots, resulting in 5,10,15,20-tetrakis (4-carboxyPheyl) (TCPP) self-assembled structure. The electrochemical chiral recognition of chiral self-assembled materials was studied using Phenylalanine (Phe) enantiomer as a chiral analyte. Electrochemical chiral recognition results showed that the chiral self-assembled materials induced by chiral templates have a good ability to discriminate Phe enantiomers. Therefore, this research provides a new idea for the synthesis of chiral composites and further expands applications to electrochemical chiral recognition.

An electrochemical chiral sensor based on glutamic acid functionalized graphene-gold nanocomposites for chiral recognition of tryptophan enantiomers

• Glu functionalized RGO-Au nanocomposites were synthesized as an electrochemical chiral sensor. • The electrochemical chiral sensor has high chiral recognition capability for Trp enantiomers. • Mechanism and binding thermodynamics were explained by UV–vis and DFT in detail. A novel chiral sensing platform via the glutamic acid (Glu) functionalized graphene-gold nanoparticles (RGO-Au/ l -Glu and RGO-Au/ d -Glu) synthesized via the one-step hydrothermal method is described for the enantioselective recognition of L- and d -tryptophan (Trp). The SEM, TEM, EDS, AFM, FTIR, and XRD characterization techniques showed that RGO-Au/ l -Glu and RGO-Au/ d -Glu chiral composite were successfully synthesized. By combining the chiral features of Glu and the excellent electrochemical behaviors of RGO-Au, two electrochemical chiral sensing interfaces constructed by RGO-Au/ l -Glu and RGO-Au/ d -Glu modified glassy carbon electrode (GCE) were constructed for electrochemical chiral recognition of Trp enantiomers. The results demonstrated that the RGO-Au/ l -Glu/GCE showed the highest chiral recognition efficiency, the enantioselectivity coefficient (I L /I D ) was 2.56. UV–vis absorption spectroscopy and density functional theory (DFT) calculations proved that RGO-Au/ l -Glu had a strong binding ability with l -Trp. In addition, the chiral sensing interface had a linear response in the 1 mM to 5 mM Trp concentration range and a 0.28 mM detection limit (at S/N = 3) for l -Trp, and 0.86 mM to d -Trp, also had good stability and reproducibility, which can be used as an efficient chiral sensing interface for the recognition of Trp enantiomers.

Drop-coated molybdenum disulfide-ionic liquid for improving the electrochemical chiral recognition ability of chitosan

A faithful and facile strategy to significantly improve the electrochemical chiral recognition ability of chitosan is proposed via drop-coating molybdenum disulfide-ionic liquid (MoS 2 -IL) nanocomposite. • MoS 2 -IL was first used to improve the enantiorecognition ability of CS. • There is a good linear relationship between the DPV peak potential and ee. • The proposed sensor exhibited satisfactory reproducibility and stability. • The proposed sensor exhibited enantiorecognition ability for other enantiomers. A faithful strategy to significantly improve the enantiorecognition ability of chitosan (CS) is proposed via drop-coating molybdenum disulfide (MoS 2 )-ionic liquid (IL) nanocomposite. The present work describes a novel, simple, and effective chiral interface based on MoS 2 -IL/CS nanocomposite which was elaborately integrated to combine the electrical signal amplification and space complexity of MoS 2 -IL and vast enantiorecognition sites of CS for the electrochemical enantiorecognition of tryptophan (Trp) enantiomers. Differential pulse voltammetry (DPV) was adopted to evaluate the potential differences (ΔE P ) between the oxidation peaks of l -Trp and d -Trp. MoS 2 -IL/CS nanocomposite showed higher chiral recognition ability result from spatial asymmetry of MoS 2 -IL/CS. Herein, several parameters, such as drop-coated volume and concentration of MoS 2 -IL, electrodeposited viscosity, time and temperature of CS, detection temperature and pH were optimized in order to obtain a large ΔE P signal between l -Trp and d -Trp, and the ΔE P value can reach 53.3 mV under optimal conditions. Furthermore, different percentages of Trp mixtures and DPV peaks potential were detected with a good linear relationship even in the real sample, which indicated that MoS 2 -IL/CS chiral interface could effectively quantify the enantiomer excess (ee) of Trp enantiomers in Trp mixtures.

Electrochemical chiral recognition of tryptophan enantiomers based on copper-modified β-cyclodextrin

An electrochemical chiral sensing platform was fabricated by successive modification of Au@Pt bimetallic nanoparticles, poly(cysteine), and Cu 2 -β-CD on the surface of glassy carbon electrode. Good conductivity and high surface area of Au@Pt endowed the sensor with high sensitivity. Cu 2 -β-CD enabled the sensor to effectively identify tryptophan (Trp) enantiomers upon the host–guest interaction with a high the oxidation peak current ratio (I L /I D ) of 2.38. Thus, the simple and efficient sensor can be used for the discrimination of Trp enantiomers. • Cu 2 -β-CD can discriminate Trp enantiomers based on the host–guest interaction. • Au@Pt bimetallic nanoparticles improved the sensitivity of the sensor. • Sensor showed excellent enantioselectivity toward Trp enantiomers. • Facile preparation facilitates the present approach promising. A novel electrochemical chiral sensor was constructed for the discrimination of Tryptophan (Trp) by the modification of Au@Pt bimetallic nanoparticles, poly(cysteine) (PL-Cys), and Cu 2+ -modified β-cyclodextrin (Cu 2 -β-CD) on the surface of glassy carbon electrode. The constructed sensor was characterized by transmission electron microscopy, infrared spectroscopy, UV–vis adsorption spectra, and the electrochemical experiments. The modified Au@Pt endowed the sensor with high surface area and good conductivity. The electropolymerized PL-Cys facilitated the loading of Cu 2 -β-CD based on the electrostatic interaction. As a chiral selector, Cu 2 -β-CD enabled the sensor to effectively identify the Trp enantiomers based on the host–guest interaction with a high the oxidation peak current ratio (I L /I D, I L and I D were the oxidation peak currents of l -Trp and d -Trp measured on the sensor, respectively) of 2.38. Under the optimized conditions, I L /I D increased with the increase of l -Trp in the raceme solution, which was further employed for the detection of Trp in serum samples with satisfactory results. With the good selectivity, stability, and reproducibility, the present electrochemical sensor can be used for the simple, rapid, and efficient chiral recognition and real samples determination.

Grain-like chiral metal-organic framework/multi-walled carbon nanotube composited electrosensing interface for enantiorecognition of Tryptophan

Due to the widespread application of chiral substances in current society, the electrochemical strategy to assemble chiral metal–organic frameworks (CMOFs) as sensors has shown great potential for sensitive enantiorecognition. In this paper, an efficient and highly selective electrochemical sensor was proposed based on multi-walled carbon nanotube (MWCNT) and CMOF, and successfully achieved sensitive chiral recognition of Tryptophan (Trp) enantiomers. Numerous MOFs in multiple synthesis conditions were investigated for a regular process to access the electrochemical chiral recognition. A variety of amino acids were introduced into the MOFs skeleton by a simple hydrothermal method for the enantio-specificity. Meanwhile the MWCNT smoothly integrated with the CMOF to form a functional electrosensing interface with the increase of conductivity. Based on the current ratio (Rcp) of tryptophan enantiomers by different modified electrodes, a series of experimental conditions were optimized for the optimal chiral recognition performance of the CMOF/MWCNT-based sensor, finally reaching 2.9 times of ΔIL/D between enantiomers. In addition, D/l-Trp showed a good linear relationship with the current in the range from 0.4 μM to 19 μM with the detection limit of 0.11 μM for l-Trp and 0.16 μM for d-Trp. The prepared composite-functionalized sensor owned the desired reproducibility and selectivity to identify Tryptophan enantiomers with robust chiral recognition. The research on the structure–activity relationship of chiral MOFs to Tryptophan enantiomers provides a new path to construct more electrochemical sensors for the application of enantiorecognition in pharmaceutical analysis.

Enantioselective recognition of tryptophan isomers with molecularly imprinted overoxidized polypyrrole/poly(p-aminobenzene sulfonic acid) modified electrode.

Poly(p-aminobenzene sulfonic acid) (pABSA) was electrodeposited onto the surface of a glassy carbon electrode (GCE), which was then used for the preconcentration of l-tryptophan (l-Trp) due to the electrostatic and π-π interactions between pABSA and l-Trp. Polypyrrole (PPy) was electrodeposited onto the surface of the l-Trp enriched pABSA, and then the l-Trp templates were removed, resulting in molecularly imprinted PPy/pABSA. To avoid the interference from the oxidation peak of PPy on the following electrochemical chiral recognition of Trp isomers, PPy was overoxidized by cyclic voltammetry (CV). The resultant molecularly imprinted overoxidized PPy (OPPy)/pABSA modified GCE exhibits higher affinity toward l-Trp than d-tryptophan (d-Trp); that is, the oxidation peak current of l-Trp is greatly higher than that of d-Trp at the molecularly imprinted OPPy/pABSA modified GCE.

Enantioselective Limiting Transport into a Fixed Cavity via Supramolecular Interaction for the Chiral Electroanalysis of Amino Acids Regardless of Electroactive Units.

Although an increasing number of researchers are developing electroanalytical protocols for the chiral recognition of amino acids, the electroactive units of the tested isomers still need to provide corresponding electrical signals. In this study, a supramolecular system was developed for the chiral electroanalysis of amino acids regardless of electroactive units. As a model system, an enantiopure electroactive molecule Fc-(S,S)-1 that includes a ferrocenyl group was synthesized and acted as a guest. Moreover, hydrophobic cyclobis-(paraquat-p-phenylene) (CBPQT4+-2) was used as the host. In the presence of π-π stacking and the attraction of π-electrons, CBPQT4+-2 can encapsulate Fc-(S,S)-1 into its cavity. Next, a screen-printed electrode was utilized for electrochemical chiral recognition. The host was fixed on the surface of the working electrode, and the guest was used as the electroactive chiral selector to support electron transfer. Once different configurations of amino acids (threonine, histidine, glutamine, and leucine) were mixed with the guest, regardless of whether they contained electroactive units, differences in the cyclic voltammetry results of the probe enantiomers could be observed, namely, in the peak currents or peak potentials. However, glutamine was an exception because the L-isomer had a stronger binding affinity with Fc-(S,S)-1 + Cu(II), which would limit the transport of the complex into the cavity of CBPQT4+-2, thereby resulting in a low peak current. Thus, an inverse phenomenon was observed with glutamine. In summary, we believe that this work can increase the testing scope for the chiral recognition of different kinds of isomers using electrochemical tools.

Chiral PDTDH-based electrode modification material for L/D-tartaric acid electrochemical sensing

In this work, a kind of chiral helical polymer PDTDH of 9,9-dipropynylfluorene skeleton structure were prepared. The structure and chiral properties of the obtained polymer were characterized by Nuclear Magnetic Resonance (NMR) and Circular Dichroism (CD) Spectroscopy. These chiral PDTDH polymers were used to fabricate chiral sensors and to investigate the enantioselective recognition of D−/L- tartaric acid enatiomer. The results indicated that the (S)-PDTDH/GCE sensor showed obvious response toward the tested tartaric acid enantiomer, which was confirmed by two parameters: Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) tests. These findings expand the scope for the application of chiral polymer as electrode modification material in the electrochemical chiral recognition field.

Electrochemical Chiral Recognition for a Complex System Based on Specific Enzymatic Reactions

Chiral recognition is facing serious challenges in achieving quantitative determination for a definite isomer in a complex sample. Herein, by introducing respectively β-D-glucose oxidase (β-D-GOD) and glucose (Glu) enantiomers (D-, L-Glu) as a model enzyme and analytes as well as carbon nanotubes (CNTs) to immobilize β-D-GOD and accelerate electron transfer processes, an electrochemical chiral sensing platform on the basic of the specific enzymatic reactions was proposed for the first time in chiral recognition. Owing to the high specificity of enzyme, many enzymes can catalyze selectively one enantiomer reaction but have little ability to catalyze the other enantiomers and interferents, resulting that the chiral sensors based on the specific enzymatic reactions have high selectivity and can be used for the direct and selective detection of enantiomer in the complex samples. It’s believed the proposed electrochemical chiral recognition strategy based on specific enzymatic reactions will have important application values for direct determination of enantiomer in real samples.

Improved chiral electrochemical recognition of tryptophan enantiomers based on three-dimensional molecularly imprinted overoxidized polypyrrole/MnO2 /carbon felt composites.

A three-dimensional molecularly imprinted overoxidized polypyrrole/MnO2 /carbon felt (MIOPPy/MnO2 /CF) composites were fabricated, which results in increased active area of the surface of the molecularly imprinted polymers film and greatly improved electrochemical chiral recognition effect for tryptophan isomers. The composites were characterized by field emission scanning electron microscope, transmission electron microscope, X-ray diffractometer, UV-visible spectra, N2 adsorption-desorption isotherms, and electrochemical methods. The manuscript provides a proof of concept and shows promising potential of the prepared composites for chiral recognition.

Perylene-functionalized graphene sheets modified with chitosan for voltammetric discrimination of tryptophan enantiomers.

A composite was prepared from graphene functionalized with 3,4,9,10-perylene tetracarboxylic acid and chitosan (rGO-PTCA-chitosan) by a chemical method. It involves non-covalent functionalization of rGO with PTCA followed by amidation reaction with chitosan. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and electrochemical methods were used to characterize the composites. By combining the chiral features of chitosan and the excellent electrochemical behaviors of rGO-PTCA, a graphene-based material with enantioselectivity was constructed for electrochemical chiral recognition of tryptophan (Trp) enantiomers. A glassy carbon electrode (GCE) modified with rGO-PTCA-chitosan had a higher recognition capability for L-Trp than for D-Trp. Best operated at a working voltage near 0.78 V (vs. SCE), the enantioselectivity coefficient is 3.0. The sensor has a linear response in the 1mM to 10mM Trp concentration range and a 1.2μM detection limit (at S/N= 3) for L-Trp, and of 3.0μM to D-Trp. The sensor was successfully used to detect Trp enantiomers in real samples, and a recognition mechanism is presented. Graphical abstract Schematic presentation of a composoie prepared by graphene functionalized with 3,4,9,10-perylene tetracarboxylic acid and chitosan (rGO-PTCA-chitosan) via a chemical method. It involves non-covalent functionalization of rGO with PTCA followed by amidation reaction with chitosan and voltammetric determination of tryptophan enantiomers.

Enantiomers of Single Chirality Nanotube as Chiral Recognition Interface for Enhanced Electrochemical Chiral Analysis.

Although separation of single-walled carbon nanotubes (SWCNTs) according to their helicity and handedness has been attracting tremendous interest recently, exploration of the left- and right-handed SWCNT enantiomers (defined as "M" and "P") to chiral sensing still remains in the early stage. Here we presented a new electrochemical sensor for chiral discrimination, which for the first time amplified the chiral selection on the electrode surface based on the left- or right-handed semiconducting SWCNT enantiomers with (6,5)-enriched chirality. The enantioselectivity was demonstrated by different peak current response to analyte enantiomers, observed in differential pulse voltammogram (DPV). Chiral distinguishing might be a result of the formation of an efficient chiral nanospace originating from the high purity of single enantiomer of (6,5) SWCNT. The obtained chiral electrodes were also applied to determine the enantiomeric excess (ee) of DOPA. There was a good linear relationship between DPV peak currents and % ee of l-DOPA. This study is the first example showing how the structure of chiral SWCNTs influences electrochemical chiral recognition.

Review—Recent Advances in Electrochemical Chiral Recognition

Chirality has an important impact in chemical and biological research, since most active substances possess chirality. Usually, the performance and properties of chiral enantiomers exhibit significant differences in terms of biochemical activity, toxicity, transport mechanism and pathways of metabolism. Thus, developing effective method to achieve chiral recognition is of great significance and has always been a hot topic in chemo/biological study. In recent years, the electrochemical technologies, which can offer many advantages over the other conventional methods, have received considerable attention in chiral recognition. In this review, a comprehensive and critical detail of the trends on electrochemical chiral recognition in the last 5 years have been presented. In addition, some critical challenges and prospects in the field of electrochemical chiral recognition are also discussed in the latter part.