A Molecularly Imprinted Electrochemical Sensor Based on TiO2@Ti3C2Tx for Highly Sensitive and Selective Detection of Chlortetracycline.

In view of the serious side effects of chlortetracycline (CTC) on the human body, it is particularly important to develop rapid, sensitive, and selective technologies for the detection of CTC in food. In this work, a molecularly imprinted electrochemical sensor with [Fe(CN)6]3-/4- as signal probe was proposed for the highly sensitive and selective detection of CTC. For this purpose, TiO2, which acts as an interlayer scaffold, was uniformly grown on the surface of Ti3C2Tx sheets through a simple two-step calcination process using Ti3C2Tx as the precursor to effectively avoid the stacking of Ti3C2Tx layers due to hydrogen bonding and van der Waals forces. This endowed TiO2@Ti3C2Tx with large specific surface, abundant functional sites, and rapid mass transfer. Then, polypyrrole molecularly imprinted polymers (MIPs) with outstanding electrical conductivity were modified on the surface of TiO2@Ti3C2Tx via simple electro-polymerization, where the pyrrole was employed as a polymeric monomer and the CTC provided a source of template molecules. This will not only provide specific recognition sites for CTC, but also facilitate electron transport on the electrode surface. The synergistic effects between TiO2@Ti3C2Tx and polypyrrole MIPs afforded the TiO2@Ti3C2Tx/MIP-based electrochemical sensor excellent detection properties toward CTC, including ultra-low limits of detection (LOD) (0.027 nM), a wide linear range (0.06-1000 nM), and outstanding stability, reproducibility, selectivity, and feasibility in real samples. The results indicate that this strategy is feasible and will broaden the horizon for highly sensitive and selective detection of CTC.

Cohering Plasma into Adhesive Gel by Natural Biopolymer-Nanoparticle Hybrid Powder for Efficient Hemostasis and Wound Healing.

Hemostatic powder is commonly used in emergency bleeding control due to its suitability for irregularly shaped wounds, ease of use, and stable storage. However, traditional powder often has limited tissue adhesion and weak thrombus support, which makes it vulnerable to displacement by blood flow. Herein, we have developed a tricomponent hemostatic powder (MQS) composed of mesoporous bioactive glass nanoparticle (MBG), positively charged quaternized chitosan (QCS), and negatively charged catechol-modified alginate (SADA). Upon application to the wound, MBG with its high specific surface area quickly absorbs plasma, concentrating the blood coagulation factor. Simultaneously, the water-soluble QCS and SADA interact with each other and form a net, which can be further cross-linked by MBG. This network efficiently binds and entraps clustered blood coagulation factors, ultimately resulting in the formation of a durable and robust thrombus. Furthermore, the formed net adheres to the injury site, offering protection against thrombus disruption caused by the bloodstream. Benefiting from the synergistic effect of these three components, MQS demonstrates superior hemostatic performance compared to commercial hemostatic powders like Celox in both arterial injuries and noncompressible liver puncture wounds. Furthermore, MQS can effectively accelerate wound healing. In addition, MQS exhibits excellent antibacterial activity, cytocompatibility, and hemocompatibility. These advantages of MQS, including strong blood clotting, wet tissue adherence, antibacterial activity, wound healing ability, biosafety, ease of use, and stable storage, make it a promising hemostatic agent for emergency situations.

Coagulating blood into adhesive gel by hybrid powder based on oppositely charged polysaccharide/tannic acid-modified mesoporous bioactive glass.

Hemostatic powder is widely utilized in emergency situations to control bleeding due to its ability to work well on wounds with irregular shapes, ease of application, and long-term stability. However, traditional powder often suffers from limited tissue adhesion and insufficient support for blood clot formation, leaving it susceptible to displacement by the flow of blood. This study introduces a hemostatic powder composed of tannic modified mesoporous bioactive glass (TMBG), cationic quaternized chitosan (QCS), and anionic hyaluronic acid modified with catechol group (HADA). The resulting TMBG/QCS/HADA based hemostatic powder (TMQH) rapidly absorbs plasma, concentrating blood coagulation factors. Simultaneously, the water-soluble QCS and HADA interact to form a 3D network structure, which can be strengthened by crosslinking with TMBG. This network effectively captures clustered blood coagulation factors, leading to a strong and adhesive thrombus that resists disruption from blood flow. TMQH exhibits superior efficacy in promoting hemostasis compared to Celox™ both in rat arterial injuries and non-compressible liver puncture wounds. TMQH demonstrates excellent antibacterial activity, cytocompatibility, and blood compatibility. These outstanding superiorities in blood clotting capability, wet tissue adhesion, antibacterial activity, safety for living organisms, ease of application, and long-term stability, make TMQH highly suitable for emergency hemostasis.

Double signal ratiometric electrochemical riboflavin sensor based on macroporous carbon/electroactive thionine-contained covalent organic framework.

Riboflavin (RF) is one of the necessary vitamins. If human body lacks RF, it will lead to inflammation and dysfunction of mouth, lips and skin. Thus sensitive and accurate determination of RF is necessary. Here, an electroactive covalent-organic framework nanobelt (COFTFPB-Thi) with thickness of 1.4 nm was prepared by amine-aldehyde condensation reaction between thionine and 1, 3, 5-tris (p-formylphenyl) benzene, which was then grown vertically on three-dimensional porous carbon derived from kenaf stem (3D-KSC) for double signal ratiometric electrochemical detection of RF. The resulted 3D-KSC/COFTFPB-Thi showed two reduction peaks at -0.08 V and -0.23 V, which came from the reduction of COFTFPB-Thi and the conjugated structure of COFTFPB-Thi, respectively. In the presence of RF, those RF molecules near the electrode surface were oxidized at 0.6 V. Then some oxidized RF (RFox) adsorbed on COFTFPB-Thi would oxidize COFTFPB-Thi into COFTFPB-Thi(ox) while other RFox adsorbed on 3D-KSC kept unchanged. When the potential was scanned from 0.6 V to -0.6 V, both COFTFPB-Thi(ox) and RFox adsorbed on 3D-KSC were reduced at -0.08 V and -0.45 V accordingly, while the reduction peak of -0.23 V of the conjugated structure of COFTFPB-Thi kept constant. When j-0.45/j-0.23 was used as the response signal, the detection limit was 44 nM and the linear range was 0.13 µM -0.23 mM. By using j-0.08/j-0.23 as the response signal, a detection limit of 90 nM and a linear range of 0.30 µM-0.23 mM (S/N = 3) were obtained. By using double signals, the measurement results can be corrected to make the results more accurate and reliable. The sensor also showed good selectivity, reproducibility and stability, which provided a good application prospects.