On-Site Visualization Assay for Tumor-Associated miRNAs: Using Ru@TiO2 as a Peroxidase-like Nanozyme.

Accurate diagnosis of highly aggressive and deadly tumors is essential for effective treatment and improved patient outcomes, and microRNAs (miRNAs) have emerged as crucial biomarkers for their roles in tumor initiation, progression, and metastasis. Herein, we present an on-site visualization colorimetric assay for tumor-associated miRNAs using ruthenium nanoparticle decorated titanium dioxide nanoribbon (Ru@TiO2) as a peroxidase-like (POD) nanozyme. Remarkably, the Ru@TiO2 nanozyme can catalyze the oxidation of chromogenic substrates through its POD-like activity, which is effectively inhibited by pyrophosphate generated during the rolling circle amplification process, thereby enabling miRNA detection through a visible colorimetric readout. This approach provides a highly sensitive and specificity assay for miRNAs in diluted human serum with a detection limit of 100 pM. It shows great potential for clinical diagnostics and biological research, offering a promising tool for early cancer diagnosis and molecular diagnostics.

Electrochemical cytosensors for non-invasive liquid biopsy: Detection procedures and technologies for circulating tumor cells.

Each year, millions of new cancer cases and cancer-related deaths underscore the urgent need for effective, affordable screening methods. Circulating tumor cells (CTCs), which derived from tumors and shedding into bloodstream, are considered promising biomarkers for liquid biopsy due to their unique biological significance and the substantial volume of supporting research. Among many advanced CTCs detection methods, electrochemical sensing is rapidly developing due to their high selectivity, high sensitivity, low cost, and rapid detection capability, well meeting the growing demand for non-invasive liquid biopsy. This review focuses on the entire procedure of detecting CTCs using electrochemical cytosensors, starting from sample preparation, detailing bio-recognition elements for capturing CTCs, highlighting design strategies of cytosensor, and discussing the prospects and challenges of electrochemical cytosensor applications.

Immuno-Rolling Circle Amplification (Immuno-RCA): Biosensing Strategies, Practical Applications, and Future Perspectives.

In the rapidly evolving field of life sciences and biomedicine, detecting low-abundance biomolecules, and ultraweak biosignals presents significant challenges. This has spurred a rapid development of analytical techniques aiming for increased sensitivity and specificity. These advancements, including signal amplification strategies and the integration of biorecognition events, mark a transformative era in bioanalytical precision and accuracy. A prominent method among these innovations is immuno-rolling circle amplification (immuno-RCA) technology, which effectively combines immunoassays with signal amplification via RCA. This process starts when a targeted biomolecule, such as a protein or cell, binds to an immobilized antibody or probe on a substrate. The introduction of a circular DNA template triggers RCA, leading to exponential amplification and significantly enhanced signal intensity, thus the target molecule is detectable and quantifiable even at the single-molecule level. This review provides an overview of the biosensing strategy and extensive practical applications of immuno-RCA in detecting biomarkers. Furthermore, it scrutinizes the limitations inherent to these sensors and sets forth expectations for their future trajectory. This review serves as a valuable reference for advancing immuno-RCA in various domains, such as diagnostics, biomarker discovery, and molecular imaging.

Ni@TiO2 nanoribbon array electrode for high-efficiency non-enzymatic glucose biosensing.

The exploration of noble metal-free nanoarrays as high-activity catalytic electrodes for glucose biosensing holds great significance. Herein, we propose a Ni nanoparticle-decorated TiO2 nanoribbon array on a titanium plate (Ni@TiO2/TP) as an effective non-enzymatic glucose biosensing electrode. The as-prepared Ni@TiO2/TP electrode demonstrates rapid glucose response, a wide linear response range (1 µM to 1 mM), a low detection limit (0.08 µM, S/N = 3), and high sensitivity (10 060 and 3940 µA mM-1 cm-2), with good mechanical flexibility and stability. Moreover, it proves efficient in glucose biosensing in real human blood serum and cell culture fluid. Thus, it is highly promising for practical applications.

Ion-sensitive field effect transistor biosensors for biomarker detection: current progress and challenges.

The ion-sensitive field effect transistor (ISFET) has emerged as a crucial sensor device, owing to its numerous benefits such as label-free operation, miniaturization, high sensitivity, and rapid response time. Currently, ISFET technology excels in detecting ions, nucleic acids, proteins, and cellular components, with widespread applications in early disease screening, condition monitoring, and drug analysis. Recent advancements in sensing techniques, coupled with breakthroughs in nanomaterials and microelectronics, have significantly improved sensor performance. These developments are steering ISFETs toward a promising future characterized by enhanced sensitivity, seamless integration, and multifaceted detection capabilities. This review explores the structure and operational principles of ISFETs, highlighting recent research in ISFET biosensors for biomarker detection. It also examines the limitations of these sensors, proposes potential solutions, and anticipates their future trajectory. This review aims to provide a valuable reference for advancing ISFETs in the field of biomarker measurement.

Ag@TiO2 nanoribbon array: a high-performance sensor for electrochemical non-enzymatic glucose detection in beverage sample.

Developing an accurate, cost-effective, reliable, and stable glucose detection sensor for the food industry poses a significant yet challenging endeavor. Herein, we present a silver nanoparticle-decorated titanium dioxide nanoribbon array on titanium plate (Ag@TiO2/TP) as an efficient electrode for non-enzymatic glucose detection in alkaline environments. Electrochemical evaluations of the Ag@TiO2/TP electrode reveal a broad linear response range (0.001 mM - 4 mM), high sensitivity (19,106 and 4264 µA mM-1 cm-2), rapid response time (6 s), and a notably low detection limit (0.18 µM, S/N = 3). Moreover, its efficacy in measuring glucose in beverage samples shows its practical applicability. The impressive performance and structural benefits of the Ag@TiO2/TP electrode highlight its potential in advancing electrochemical sensors for small molecule detection.

Boosting Alkaline Seawater Oxidation of CoFe-layered Double Hydroxide Nanosheet Array by Cr Doping.

The pursuit of stable and efficient electrocatalysts toward seawater oxidation is of great interest, yet it poses considerable challenges. Herein, the utilization of Cr-doped CoFe-layered double hydroxide nanosheet array is reported on nickel-foam (Cr-CoFe-LDH/NF) as an efficient electrocatalyst for oxygen evolution reaction in alkaline seawater. The Cr-CoFe-LDH/NF catalyst can achieve current densities of 500 and 1000 mA cm -2 with remarkably low overpotentials of only 334 and 369 mV, respectively. Furthermore, it maintains at least 100 h stability when operated at 500 mA cm-2.

A portable all-in-one microfluidic device with real-time colorimetric LAMP for HPV16 and HPV18 DNA point-of-care testing.

Screening for high-risk human papillomavirus (HPV) infection is one of the most important preventative measures for cervical cancer. However, fast, convenient, and low-cost HPV detection remains challenging, especially in resource-limited settings. Here, we report a portable all-in-one device (PAD) for point-of-care testing (POCT) for HPV16 and HPV18 DNA in cervical swabs. The PAD was engineered to integrate modules for extraction-free sample lysis, loop-mediated isothermal amplification (LAMP) with lyophilized reagent beads, and real-time colorimetric signal sensing into a single miniaturized device, considerably shortening the sample-to-result time to 15 min. The precision liquid handling in the completely sealed microfluidic chip is achieved by a uniquely designed pressure-balanced automatic liquid flow mechanism, thereby eliminating the need for manual manipulation of liquids and thus the risk of biohazards. The PAD employs an improved real-time colorimetric LAMP (rcLAMP) assay with a limit of detection (LOD) of 1 copy/µL, enabled by enhanced assay chemistry to maximize the reaction kinetics. To validate this device for clinical application, we tested 206 clinical cervical swab samples and obtained a sensitivity of 92.1% and a specificity of 99.0%. This custom PAD enabled by microfluidic and electronic engineering techniques can be configured for the simultaneous detection of HPV16 and HPV18 or other pathogens in point-of-care applications.

Wireless, battery-free, multifunctional integrated bioelectronics for respiratory pathogens monitoring and severity evaluation.

The rapid diagnosis of respiratory virus infection through breath and blow remains challenging. Here we develop a wireless, battery-free, multifunctional pathogenic infection diagnosis system (PIDS) for diagnosing SARS-CoV-2 infection and symptom severity by blow and breath within 110 s and 350 s, respectively. The accuracies reach to 100% and 92% for evaluating the infection and symptom severity of 42 participants, respectively. PIDS realizes simultaneous gaseous sample collection, biomarker identification, abnormal physical signs recording and machine learning analysis. We transform PIDS into other miniaturized wearable or portable electronic platforms that may widen the diagnostic modes at home, outdoors and public places. Collectively, we demonstrate a general-purpose technology for rapidly diagnosing respiratory pathogenic infection by breath and blow, alleviating the technical bottleneck of saliva and nasopharyngeal secretions. PIDS may serve as a complementary diagnostic tool for other point-of-care techniques and guide the symptomatic treatment of viral infections.

Genetic polymorphisms of rs73620203 in the transforming growth interacting factor gene associated with rheumatoid arthritis in a Chinese population.

OBJECTIVE: To explore the association of single nucleotide polymorphisms (SNPs) in the transforming growth interacting factor (TGIF) gene with bone metabolism markers and rheumatoid arthritis (RA) susceptibility. METHODS: Three SNPs were genotyped in 155 RA patients and 168 healthy controls using high-resolution melting (HRM) analysis. The serum levels of osteocalcin, bone alkaline phosphatase (BALP), and ß type I collagen-crosslinked C telopeptide (ß-CTX) were detected using electrochemical luminescence in 108 patients randomly selected from the RA group. RESULTS: Genotype and allele frequency analysis showed that rs73620203 was associated with bone erosion in RA (P = 0.012 and P = 0.003, respectively), and individuals carrying the T allele for rs73620203 showed a decreased RA risk (OR = 0.59, 95% CI = 0.42-0.84; P = 0.003). In sex-specific analysis, the rs73620203 polymorphism was associated with susceptibility to RA in women (P = 0.022 and P = 0.006, respectively). In addition, RA patients with three genotypes at the rs73620203 locus showed significant differences in serum osteocalcin and BALP (P = 0.006 and P = 0.037, respectively). Haplotype analysis revealed that the haploid ATG and GCA frequencies were significantly lower in the RA group (P = 0.036, OR = 0.693; P = 0.002, OR = 0.189, respectively), while the haploid ACA frequency of the RA group was enhanced (P < 0.01, OR = 5.058). CONCLUSION: Our study provides the first evidence that rs73620203 is associated with RA susceptibility and the relationship between TGIF gene SNPs and the regulation of bone metabolism in RA patients.

Improved Electrochemical Alkaline Seawater Oxidation over Cobalt Carbonate Hydroxide Nanowire Array by Iron Doping.

Constructing efficient and low-cost oxygen evolution reaction (OER) catalysts operating in seawater is essential for green hydrogen production but remains a great challenge. In this study, we report an iron doped cobalt carbonate hydroxide nanowire array on nickel foam (Fe-CoCH/NF) as a high-efficiency OER electrocatalyst. In alkaline seawater, such Fe-CoCH/NF demands an overpotential of 387 mV to drive 500 mA cm-2, superior to that of CoCH/NF (597 mV). Moreover, it achieves excellent electrochemical and structural stability in alkaline seawater.

Sn-based electrocatalysts for electrochemical CO2 reduction.

Electrochemical CO2 reduction into value-added chemicals represents an attractive and promising approach to capitalize on the abundant CO2 present in the atmosphere. This reaction, however, is hampered by low energy efficiency and selectivity owing to competition from hydrogen evolution reaction and multiple-electron transfer processes. Therefore, there is a pressing need to develop efficient yet cost-effective electrocatalysts to facilitate practical applications. Sn-based electrocatalysts have gained increasing attention in this active field due to their outstanding merits such as abundance, non-toxicity, and environmental friendliness. This review provides a comprehensive overview of recent advances in Sn-based catalysts for the CO2 reduction reaction (CO2RR), beginning with a brief introduction to the CO2RR mechanism. Subsequently, the CO2RR performance of various Sn-based catalysts with different structures is discussed. The article concludes by addressing the existing challenges and offering personal perspectives on the future prospects in this exciting research area.

Label-Free, High-Throughput, Sensitive, and Logical Analysis Using Biomimetic Array Based on Stable Luminescent Copper Nanoclusters and Entropy-Driven Nanomachine.

The development of an array for high-throughput and logical analysis of biomarkers is significant for disease diagnosis. DNA-templated copper nanoclusters (CuNCs) have a strong potential to serve as a label-free photoluminescence source in array platforms, but their luminescent stability and sensitivity need to be improved. Herein, we report a facile, sensitive, and robust biomimetic array assay by integrating with stable luminescent CuNCs and entropy-driven nanomachine (EDN). In this strategy, the luminescent stability of CuNCs was improved by adding fructose in CuNCs synthesis to offer a reliable label-free signal. Meanwhile, the DNA template for CuNCs synthesis was introduced into EDN with excellent signal amplification ability, in which the reaction triggered by target miRNA would cause the blunt/protruding conformation change of 3'-terminus accompanied by the production or loss of luminescence. In addition, a biomimetic array fabricated by photonic crystals (PCs) physically enhanced the emitted luminescent signal of CuNCs and achieved high-throughput signal readout by a microplate reader. The proposed assay can isothermally detect as low as 4.5 pM of miR-21. Moreover, the logical EDN was constructed to achieve logical analysis of multiple miRNAs by "AND" or "OR" logic gate operation. Therefore, the proposed assay has the advantages of label-free property, high sensitivity, flexible design, and high-throughput analysis, which provides ideas for developing a new generation of facile and smart platforms in the fields of biological analysis and clinical application.

Infrared characterization of interfacial Si-O bond formation on silanized flat SiO2/Si surfaces.

Chemical functionalization of silicon oxide (SiO(2)) surfaces with silane molecules is an important technique for a variety of device and sensor applications. Quality control of self-assembled monolayers (SAMs) is difficult to achieve because of the lack of a direct measure for newly formed interfacial Si-O bonds. Herein we report a sensitive measure of the bonding interface between the SAM and SiO(2), whereby the longitudinal optical (LO) phonon mode of SiO(2) provides a high level of selectivity for the characterization of newly formed interfacial bonds. The intensity and spectral position of the LO peak, observed upon silanization of a variety of silane molecules, are shown to be reliable fingerprints of formation of interfacial bonds that effectively extend the Si-O network after SAM formation. While the IR absorption intensities of functional groups (e.g., >C=O, CH(2)/CH(3)) depend on the nature of the films, the blue-shift and intensity increase of the LO phonon mode are common to all silane molecules investigated and their magnitude is associated with the creation of interfacial bonds only. Moreover, results from this study demonstrate the ability of the LO phonon mode to analyze the silanization kinetics of SiO(2) surfaces, which provides mechanistic insights on the self-assembly process to help achieve a stable and high quality SAM.

Nano-confinement induced chain alignment in ordered P3HT nanostructures defined by nanoimprint lithography.

Control of polymer morphology and chain orientation is of great importance in organic solar cells and field effect transistors (OFETs). Here we report the use of nanoimprint lithography to fabricate large-area, high-density, and ordered nanostructures in conjugated polymer poly(3-hexylthiophene) or P3HT, and also to simultaneously control 3D chain alignment within these P3HT nanostructures. Out-of-plane and in-plane grazing incident X-ray diffraction were used to determine the chain orientation in the imprinted P3HT nanostructures, which shows a strong dependence on their geometry (gratings or pillars). Vertical chain alignment was observed in both nanogratings and nanopillars, indicating strong potential to improve charge transport and optical properties for solar cells in comparison to bulk heterojunction structure. For P3HT nanogratings, pi-pi stacking along the grating direction with an angular distribution of +/-20 degrees was found, which is favorable for OFETs. We propose the chain alignment is induced by the nanoconfinement during nanoimprinting via pi-pi interaction and hydrophobic interaction between polymer chain and mold surfaces.

Cell encapsulation and oxygenation in nanoporous microcontainers.

With strides in stem cell biology, cell engineering and molecular therapy, the transplantation of cells to produce therapeutic molecules endogenously is an attractive and achievable alternative to the use of exogenous drugs. The encapsulation of such cell transplants in semi-permeable, nanoporous constructs is often required to protect them from immune attack and to prevent their proliferation in the host. However, effective graft immunoisolation has been mostly elusive owing to the absence of a high-throughput method to create precisely controlled, high-aspect-ratio nanopores. To address the clinical need for effective cell encapsulation and immunoisolation, we devised a biocompatible cell-encapsulating microcontainer and a method to create highly anisotropic nanopores in the microcontainer's surface. To evaluate the efficacy of these nanopores in oxygenating the encapsulated cells, we engineered 9L rat glioma cells to bioluminesce under hypoxic conditions. The methods described above should aid in evaluating the long term survival and efficacy of cellular grafts.

Deposition of DNA rafts on cationic SAMs on silicon [100].

We demonstrate a guided self-assembly approach to the fabrication of DNA nanostructures on silicon substrates. DNA oligonucleotides self-assemble into "rafts" 8 x 37 x 2 nm in size. The rafts bind to cationic SAMs on silicon wafers. Electron-beam lithography of a thin poly(methyl methacrylate) (PMMA) resist layer was used to define trenches, and (3-aminopropyl)triethoxysilane (APTES), a cationic SAM precursor, was deposited from aqueous solution onto the exposed silicon dioxide at the trench bottoms. The remaining PMMA can be cleanly stripped off with dichloromethane, leaving APTES layers 0.7-1.2 nm in thickness and 110 nm in width. DNA rafts bind selectively to the resulting APTES stripes. The coverage of DNA rafts on adjacent areas of silicon dioxide is 20 times lower than on the APTES stripes. The topographic features of the rafts, measured by AFM, are identical to those of rafts deposited on wide-area SAMs. Binding to the APTES stripes appears to be very strong as indicated by "jamming" of the rafts at a saturation coverage of 42% and the stability to repeated AFM scanning in air.