Dual molecular recognition strategy for highly sensitive electrochemical detection of dopamine based on amplification of DNA–Au bio–bar codes

Construction of a Dye-Sensitized and Gold Plasmon-Enhanced Cathodic Photoelectrochemical Biosensor for Methyltransferase Activity Assay

DNA methyltransferases may function as important biomarkers of cancers and genetic diseases. Herein, we develop a dye-sensitized and gold plasmon-enhanced cathodic photoelectrochemical (PEC) biosensor on the basis of p-type covalent organic polymers (COPs) for the signal-on measurement of M.SssI methyltransferase (M.SssI MTase). The cathodic PEC biosensor is constructed by the in situ growth of p-type COP films onto a glass coated with indium tin oxide and the subsequent assembly of biotin- and HS-labeled double-stranded DNA (dsDNA) probes onto the COP film via biotin-streptavidin interaction. The dsDNA probe contains the recognition sequence of M.SssI MTase. The COP thin films possess a porous ultrathin nanosheet structure with abundant active sites, facilitating the generation of a high photocurrent compared with the hydrothermally synthesized ones. The presence of DNA methyltransferases can prevent the digestion of restriction endonuclease HpaII, consequently inducing the introduction of gold nanoparticles (AuNPs) to the dsDNA probes via the S-Au bond and the intercalation of rhodamine B (RhB) into the DNA grooves to produce a high photocurrent due to the dye-photosensitized enhancement and AuNP-mediated surface plasmon resonance. However, in the absence of M.SssI MTase, HpaII digests the dsDNA probes, and neither AuNPs nor RhB can be introduced onto the electrode surface, leading to a low photocurrent. This cathodic PEC biosensor possesses high sensitivity and good selectivity, and it can screen the inhibitors and detect M.SssI MTase in serum as well.

Bipolar Aggregation-Induced Electrochemiluminescence of Thiophene-Fused Conjugated Microporous Polymers

Herein, we synthesize the thiophene tetraphenylethene-based conjugated microporous polymer (ThT-CMP) using the tetraphenylethylene derivative [i.e., 1,1,2,2-tetrakis(4-bromophenyl)ethane (TPBE)] and 2,5-thiophenediboronic acid as the precursors. The aggregation of TPBE in the ThT-CMP can induce a strong dual-band bipolar electrochemiluminescence (AIECL) emission at 554 nm (anodic) and 559 nm (cathodic) with tri-n-propylamine (TPrA) and S₂O₈^2- as the coreactants, respectively. The anodic and cathodic ECL efficiencies are measured to be 11.49 and 3.82% with respect to the standard of the Ru(bpy)₃²⁺/TPrA system, respectively. We further develop a dipolar ECL sensor to sensitively detect rhodamine B (RhB) based on resonance energy transfer. This ECL sensor possesses a large dynamic range and high sensitivity. This research provides a new avenue of designing organic structures with the characteristic of bipolar AIECL for the development of luminescent devices.

Recent advances of the ionic chiral selectors for chiral resolution by chromatography, spectroscopy and electrochemistry

Ionic chiral selectors have been received much attention in the field of asymmetric catalysis, chiral recognition, and preparative separation. It has been shown that the addition of ionic chiral selectors can enhance the recognition efficiency dramatically due to the presence of multiple intermolecular interactions, including hydrogen bond, π-π interaction, van der Waals force, electrostatic ion-pairing interaction, and ionic-hydrogen bond. In the initial research stage of the ionic chiral selectors, most of work center on the application in chromatographic separation (capillary electrophoresis, high-performance liquid chromatography, and gas chromatography). Differently, more and more attention has been paid on the spectroscopy (nuclear magnetic resonance, fluorescence, ultraviolet and visible absorption spectrum, and circular dichroism spectrum) and electrochemistry in recent years. In this tutorial review as regards the ionic chiral selectors, we discuss in detail the structural features, properties, and their application in chromatography, spectroscopy, and electrochemistry.

Artificial Bioaugmentation of Biomacromolecules and Living Organisms for Biomedical Applications

The synergistic union of nanomaterials with biomaterials has revolutionized synthetic chemistry, enabling the creation of nanomaterial-based biohybrids with distinct properties for biomedical applications. This class of materials has drawn significant scientific interest from the perspective of functional extension via controllable coupling of synthetic and biomaterial components, resulting in enhancement of the chemical, physical, and biological properties of the obtained biohybrids. In this review, we highlight the forefront materials for the combination with biomacromolecules and living organisms and their advantageous properties as well as recent advances in the rational design and synthesis of artificial biohybrids. We further illustrate the incredible diversity of biomedical applications stemming from artificially bioaugmented characteristics of the nanomaterial-based biohybrids. Eventually, we aim to inspire scientists with the application horizons of the exciting field of synthetic augmented biohybrids.