A photothermal effect-based chiral sensor for chiral discrimination and sensitive detection.

Chiral analysis with simple devices is of great importance for analytical chemistry. Based on the photothermal (PT) effect, a simple chiral sensor with a portable laser device as the light source and a thermometer as the detection tool was developed for the chiral recognition of tryptophan (Trp) isomers and the sensitive sensing of one isomer (L-Trp). Gold nanorods (GNRs), which have outstanding photo-thermal conversion ability due to their localized surface plasma resonance (LSPR) effect, are used as PT reagents, and biomacromolecules bovine serum albumin (BSA) are used as natural chiral sources, and thus, GNRs@BSA was obtained through Au-S bonds.

A mesothelin microsensor based on an embedded thionine electronic medium within an imprinted polymer on an acupuncture needle electrode.

An electrochemical microsensor for mesothelin (MSLN) based on an acupuncture needle (AN) was constructed in this work. To prepare the microsensor, MSLN was self-assembled on 4-mercaptophenylboronic acid (4-MPBA) by an interaction force between the external -diol and phenylboronic acid. This was followed by the gradual electropolymerization of thionine (TH) and eriochrome black T (EBT) around the anchored protein.

Visual and electrochemical chiral discrimination of tryptophan isomers with shikimic acid chiral ionic liquids-copper ions complex.

Efficient discrimination of amino acids (AAs) isomers is of significant importance for life science and analytical chemistry. Here, a dual-mode chiral discrimination strategy is proposed for visual and electrochemical chiral discrimination of tryptophan (Trp) isomers. Shikimic acid chiral ionic liquids (SCIL) is coordinated with copper ions (Cu), and the obtained SCIL-Cu can form ternary complexes with the Trp isomers.

Carboxymethyl potato starch hydrogels encapsulated cyclodextrin metal-organic frameworks for enantioselective loading of S-naproxen and its programmed release.

A natural polysaccharide-based vehicle is facilely prepared for enantioselective loading of S-naproxen (S-NPX) and its programmed release. Cyclodextrin metal-organic frameworks (CD-MOF) are synthesized through the coordination of K with γ-cyclodextrin (γ-CD). Compared with R-NPX, the CD-MOF preferably combines with S-NPX, which can be confirmed by the thermodynamic calculations.

Fabrication of CoSe/CoP with rich selenium- and phosphorus-vacancies and heterogeneous interfaces for asymmetric supercapacitors.

CoSe/CoP with rich Se- and P-vacancies and heterogeneous interfaces (v-CoSe/CoP) is grown on the surface of nickel foam via a two-step strategy: electrodeposition and NaBH reduction, which can be used as the cathode material in asymmetric supercapacitors. The SEM characterization reveals the honeycomb-like structure of the v-CoSe/CoP, and the results of EPR, XPS and HRTEM reveal the existence of anionic vacancies and heterogeneous interfaces in the v-CoSe/CoP. The as-fabricated v-CoSe/CoP exhibits high specific capacitance (3206 mF cm at 1.

A highly selective and sensitive sensor for promethazine based on molecularly imprinted interface coated Au/Sn bimetal nanoclusters functionalized acupuncture needle microelectrode.

Promethazine (PMZ) is an effective antihistamine that is used as a nerve tranquilizer to treat mental disorders. However, drug abuse causes harm to the human body and also pollutes the environment to a certain extent. Therefore, it is crucial to develop a highly selective and sensitive biosensor for PMZ determination.

A surface molecularly imprinted electrochemical biosensor for the detection of SARS-CoV-2 spike protein by using CuS-Au as built-in probe.

Sensitive detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) spike protein (S protein) is of significant clinical importance in the diagnosis of COVID-19 pandemic. In this work, a surface molecularly imprinted (SMI) electrochemical biosensor is fabricated for the detection of SARS-CoV-2 S protein. CuS-Au is used as the built-in probe and modified on the surface of a screen-printed carbon electrode (SPCE).

An electrochemical chlorpromazine sensor based on a gold-copper bimetallic synergetic molecularly imprinted interface on an acupuncture needle electrode.

Chlorpromazine (CPZ) is a medicine for nervous system disorders. Measuring CPZ can assist doctors in evaluating patients' blood drug concentration and monitoring drug metabolism. Therefore, an accurate detection of CPZ is crucial.

A sequential delivery system based on MoS nanoflower doped chitosan/oxidized dextran hydrogels for colon cancer treatment.

A sequential delivery system based on MoS nanoflower (MoS NF) doped chitosan (CS)/oxidized dextran (OD) hydrogels is developed for the treatment of colon cancer. 5-Fluorouracil (5-FU) is combined with polyethylenimine (PEI) decorated MoS NF via electrostatic attraction and hydrogen bonding, and the obtained 5-FU/PEI/MoS is encapsulated by 1-tetradecanol (TD), a commonly used phase transition material. The resultant TD/5-FU/PEI/MoS (TFPM) is then co-encapsulated with methotrexate (MTX) in the CS/OD hydrogels generated via Schiff base reaction and electrostatic attraction.

Molecularly imprinted miniature electrochemical biosensor for SARS-CoV-2 spike protein based on Au nanoparticles and reduced graphene oxide modified acupuncture needle.

Accurate detection of SARS-CoV-2 spike (SARS-CoV-2-S) protein is of clinical significance for early diagnosis and timely treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Herein, a surface molecularly imprinted miniature biosensor was fabricated. Au nanoparticles (AuNPs), reduced graphene oxide (rGO), poly(methylene blue)/poly(ionic liquids) and poly(ionic liquids) were successively electrodeposited onto the pinpoint of an acupuncture needle (AN).

A chiral sensing platform based on a multi-substituted ferrocene-cuprous ion complex for the discrimination of electroactive amino acid isomers.

An electrochemical chiral sensing platform based on a multi-substituted ferrocene-cuprous ion (Cu) complex is constructed for the discrimination of electroactive amino acid (AA) isomers. Due to the opposite configurations of the AA isomers, the developed multi-substituted ferrocene-Cu can preferably combine with a right-handed AA (D-AA) isomer to form the ternary complex of multi-substituted ferrocene-Cu-D-AA through π-π interactions, resulting in higher peak currents of D-AA. Therefore, the isomers of electroactive AA can be successfully discriminated.

A biodegradable pH and glutathione dual-triggered drug delivery system based on mesoporous silica, carboxymethyl chitosan and oxidized pullulan.

A simple and smart drug controlled delivery system is developed in this work. Biodegradable mesoporous silica nanoparticles (BMSN) were first synthesized by introducing disulfide during the synthesis of mesoporous silica nanoparticles (MSN), which were used for the loading of methotrexate (MTX), an anti-cancer drug. The MTX loaded BMSN (BMSN-MTX) was then encapsulated in the hydrogels of carboxymethyl chitosan (CMCS)/oxidized pullulan (OPL) generated through Schiff base reaction.

An electrochemical chiral sensor based on competitive host-guest interaction for the discrimination of electroinactive amino acids.

A novel electrochemical chiral sensor has been designed based on the principle of competitive host-guest interaction and utilized for the discrimination of electroinactive proline (Pro) isomers. Electroactive methylene blue (MB) was used as the signal probe, which was combined with multi-walled carbon nanotubes (MWCNTs)-decorated β-cyclodextrin (β-CD), host-guest interaction, where the oxidation peak currents of MB decreased after isomers of Pro were combined with the MWCNTs-β-CD a competitive host-guest interaction. Due to the steric configuration of L-Pro matching the cavity of β-CD, more L-Pro than D-Pro was combined with MWCNTs-β-CD, resulting in a more pronounced decrease of MB peak currents.

Dual-template molecularly imprinted electrochemical biosensor for IgG-IgM combined assay based on a dual-signal strategy.

Detection of immunoglobulins (Igs) is of clinical significance for early diagnosis and timely treatment of diseases. Herein, a dual-template molecularly imprinted (DTMI) electrochemical biosensor was developed for IgG-IgM combined assay. In this DTMI electrochemical biosensor, Prussian blue (PB) and thionine (TH) decorated on graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs), respectively, were utilized as the dual-signal probes, and Au nanoparticles (AuNPs) were used for Igs anchoring and signal amplification.

The hybrids of perylene tetracarboxylic acid functionalized multi-walled carbon nanotubes and chitosan for electrochemical chiral sensing of tryptophan enantiomers.

To introduce abundant carboxyl (COOH) groups to the surface of multi-walled carbon nanotubes (MWCNTs) while maintaining the pristine structure of MWCNTs, 3,4,9,10-perylene tetracarboxylic acid (PTCA) was non-covalently grafted to the sidewalls of MWCNTs. The obtained PTCA functionalized MWCNTs (MWCNTs-PTCA) functioned as a scaffold for the further introduction of chitosan (CS) via electrostatic attractions and hydrogen-bonds. The resultant CS/MWCNTs-PTCA could be used for electrochemical chiral sensing of tryptophan (Trp) enantiomers due to the intrinsic chirality of CS and the high electrocatalytic activity of MWCNTs.

A surface protein-imprinted biosensor based on boronate affinity for the detection of anti-human immunoglobulin G.

A surface protein-imprinted biosensor was constructed on a screen-printed carbon electrode (SPCE) for the detection of anti-human immunoglobulin G (anti-IgG). The SPCE was successively decorated with aminated graphene (NH-G) and gold nanobipyramids (AuNBs) for signal amplification. Then 4-mercaptophenylboric acid (4-MPBA) was covalently anchored to the surface of AuNBs for capturing anti-IgG template through boronate affinity binding.

Ultrasensitive Electrochemical Impedance Chiral Discrimination and Sensing of Tryptophan Isomers Based on Core-Shell-Structured Au-Ag Nanoparticles.

Au-Ag nanoparticles (Au-Ag NPs) with a core-shell structure are prepared and used for ultrasensitive electrochemical impedance (EI) discrimination of the isomers of tryptophan (Trp). As revealed by circular dichroism, rotary polarization caused by the Au-Ag NPs is consistent with D-Trp but opposite to L-Trp, and thus, the Au-Ag NPs can selectively combine with D-Trp through preferential interactions. Compared with Au-Ag NPs, the composites of D-Trp and Au-Ag NPs (Au-Ag NPs/D-Trp) display significantly increased charge transfer resistance (); differently, the of Au-Ag NPs/L-Trp remains almost unchanged because the Au-Ag NPs exhibit poor affinity toward L-Trp.

Electrochemiluminescent chiral discrimination with chiral AgS quantum dots/few-layer carbon nitride nanosheets.

Well-dispersed chiral AgS quantum dots (AgS QDs) were facilely synthesized by using -acetyl-L-cysteine (NALC) as the chiral ligand and loaded onto nanosheets of two-dimensional (2D) few-layer carbon nitride (CN). The resultant nanocomposite (AgS QDs/few-layer CN) shows enhanced electrochemiluminescence (ECL) while maintaining the chirality of AgS QDs, which can be used for the chiral discrimination of the enantiomers of tyrosine (Tyr). Due to the higher affinity of chiral AgS QDs toward L-Tyr than toward its enantiomer, the ECL intensity of AgS QDs/few-layer CN is significantly decreased after its incubation with L-Tyr, and thus the Tyr enantiomers can be discriminated.

Dual-drug delivery system based on the hydrogels of alginate and sodium carboxymethyl cellulose for colorectal cancer treatment.

To improve the efficacy of chemotherapy and relieve the pain associated with colorectal cancer, a dual-drug delivery system (DDDS) is proposed. In this system, methotrexate (MTX) loaded CaCO (CaCO/MTX) and aspirin (Asp) are co-entrapped in the hydrogels of alginate (Alg) and sodium carboxymethyl cellulose (CMC) crosslinked with Ca. The hydrogels can protect the anti-cancer drug of MTX from being absorbed in stomach and small intestine and ensure their efficacy at the target site of colorectum.

Fluorometric discrimination of tyrosine isomers based on the inner filter effect of chiral Au nanoparticles on MoS quantum dots.

A fluorescent chiral sensor is proposed based on the inner filter effect (IFE) of chiral Au nanoparticles (AuNPs) on MoS2 quantum dots (MoS2 QDs), which can be used for the discrimination of the isomers of tyrosine (Tyr). l-Tyrosine (l-Tyr) can induce obvious agglomeration of the chiral AuNPs, leading to an attenuated IFE of the chiral AuNPs and greatly restored fluorescence of the MoS2 QDs, and thus the enantioselective recognition of the Tyr isomers can be achieved. Also, l-Tyr but not d-Tyr induced agglomeration of the chiral AuNPs is confirmed by the larger association constant between l-Tyr and the chiral sensor.

Development of a Copper-Based Metal Organic Electrode for Nitrite Sensing.

Background: Nitrite is naturally present in vegetables and added to processed meats to enhance their color and prolong their shelf life. It is of concern because it reacts to form nitrosamines, which have been linked to cancer.

Objective: To develop a quick, reliable, and inexpensive method for quantifying nitrite in foods.

Electropolymerized melamine for simultaneous determination of nitrite and tartrazine.

Poly(melamine) (PMel) was synthesized via the electropolymerization of melamine monomer, which was then characterized by field-emission scanning electron microscopy (FESEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The possible polymerization mechanisms of melamine were also revealed by FT-IR spectroscopy and UV-Vis spectroscopy. Next, the PMel modified GCE (PMel/GCE) was used for the simultaneous determination of nitrite (NO) and tartrazine, and the parameters were optimized.

Panaxdiol Saponins Component Promotes Hematopoiesis and Modulates T Lymphocyte Dysregulation in Aplastic Anemia Model Mice.

Objective: To investigate the potential efficacy of panaxadiol saponins component (PDS-C) in the treatment of aplastic anemia (AA) model mice.

Methods: Totally 70 mice were divided into 7 groups as follows: normal, model, low-, medium-, high-dose PDS-C (20, 40, 80 mg/kg, namely L-, M-, H-PDS-C), cyclosporine (40 mg/kg), and andriol (25 mg/kg) groups, respectively. An immune-mediated AA mouse model was established in BALB/c mice by exposing to 5.

Chiral Enantioselective Assemblies Induced from Achiral Porphyrin by l- and d-Lysine.

π-Conjugated porphyrins have aroused particular attention for nanofabrication and biomimics; however, little attention has been paid to porphyrins-based chiral analysis owing to the achiral feature of porphyrins. Here, we demonstrated a chiral self-assembly of achiral porphyrin induced by l- and d-lysine (l- and d-Lys), and the resultant porphyrin self-assembly exhibited alterable morphologies depending on the inducer used (l- or d-Lys). The supramolecular chirality of the self-assembly was characterized by circular dichroism (CD) spectra, confirming successful transfer of molecular chirality from l- and d-Lys to the self-assembly.

Disulfide-cleavage- and pH-triggered drug delivery based on a vesicle structured amphiphilic self-assembly.

Hydrophilic poly (acrylic acid) (PAA) and hydrophobic α-tocopherol succinate (TOS) were integrated via a two-step amidation with cystamine (Cys) as the linkage, and then the self-assembly of amphiphilic PAA-cys-TOS occurred in the aqueous solution of methotrexate (MTX), an anti-cancer drug, resulting a vesicle structured drug carrier. Since the disulfide (-S-S-) bridge of Cys is sensitive to glutathione (GSH) and the amide bonds in PAA-cys-TOS are sensitive to pH, disulfide-cleavage- and pH-triggered drug delivery was achieved with the amphiphilic self-assembly. Of particular interest was that the topography of the self-assembly varied remarkably during the triggered delivery, which was indicated by TEM results.