Microchimica Acta最新文献

A novel electrochemical aptasensor based on bimetallic zirconium and copper oxides embedded within mesoporous carbon (denoted as ZrO₂CuO_x@mC) was constructed to detect miRNA. The porous ZrO₂CuO_x@mC was created through the pyrolysis of bimetallic zirconium/copper-based metal–organic framework (ZrCu-MOF). The substantial surface area and high porosity of ZrO₂CuO_x@mC nanocomposite along with its robust affinity toward aptamer strands, facilitated the effective anchoring of aptamer strands on the ZrO₂CuO_x@mC-modified electrode surface. This, coupled with the remarkable electrochemical performance arising from the presence of metal oxides and mesoporous carbon, resulted in the exceptional sensitivity of the ZrO₂CuO_x@mC-based aptasensor for the detection of miR-21. The prepared aptasensor not only demonstrated a broad detection range from 10 zM to 100 pM, featuring an exceptionally low detection limit of 0.52 zM, but also exhibited notable selectivity against interferences. Moreover, it displayed good stability, reproducibility, and acceptable applicability for miR-21 detection in human serum. The fabricated aptasensor offers a promising platform for ultrasensitive miR-21 detection, with potential applications in accurate and early diagnosis of diseases related to miRNA.

Graphical Abstract

Compared with previous decades, healthcare has emerged as a key global concern in light of the recurrent outbreak of pandemics. The initial stage in the provision of healthcare involves the process of diagnosis. Countries worldwide advocate for healthcare research due to its efficacy and capacity to assist diverse populations. Enhanced levels of healthcare management can be attained by the implementation of rapid diagnostic procedures and cognitive data analysis. Therefore, there is a constant need for smart therapeutics, analytical tools, and diagnostic systems to improve health and well-being. The past decade witnessed enormous growth in the sensing detection systems integrated into smartphones with printed electrodes and wearable patches for the screening of various healthcare diagnostics biomarkers and therapeutic drugs. This review focuses on the expansion of point-of-care technologies and their incorporation into a broader array of portable devices, a critical aspect in the context of decentralized societies and their healthcare systems. Discussions are broadly focused on the different sensing platforms such as solid electrodes, screen-printed electrodes, and paper-based sensing strategies for the detection of various biomarkers and therapeutic drugs. We also discuss the next-generation healthcare wearable sensing device importance and future research possibilities. Finally, the portable electrochemical sensing devices and their future perspective developments towards healthcare diagnosis are critically summarized.

Graphical Abstract

Thiazolo[5,4-d]thiazole-2,5-dicarboxylic acid (H₂Thz), a thiazolothiazole (TTz) derivative with carboxylic acid groups, was synthesized as a ligand for the creation of five MOFs, each associated with distinct metal ions including Ag⁺, Mn²⁺, Co²⁺, Zn²⁺, and Cu²⁺. The cathodic electrochemiluminescence (ECL) of H₂Thz and the resulting MOFs was investigated. H₂Thz was found to generate ECL signals, but this process was heavily reliant on potassium persulfate (K₂S₂O₈) as a co-reactant. However, the Ag-MOF, formed with H₂Thz as the ligand, exhibited substantial ECL signals without the need for any co-reactant, which is different from other metal-containing MOFs. The smaller band gap, higher electron mobility and the unique electrocatalytic activity of Ag⁺ ions were confirmed to be the reasons for the excellent ECL performance of Ag-MOF. The interaction between thiol group of glutathione (GSH) and Ag-MOF suppressed the ECL signal of the Ag-MOF-K₂S₂O₈ system. Based on this, a sensitive ECL method for GSH was developed and effectively utilized for GSH quantification in cell lysates.

Graphical Abstract

The Ag-MOF, constructed from the distinctive electron-accepting properties of thiazolo[5,4-d]thiazole-2,5-dicarboxylic acid and the superior catalytic and conductive attributes of silver, was utilized as an elecetrochemiluminescence probe for the sensitive determination of glutathione in cell lysates

A self-powered dual-electrode aptasensor was developed for the detection of tumor marker carcinoembryonic antigen (CEA). The composite BiVO₄/ZnIn₂S₄, which is capable of forming a Z-scheme heterojunction, was chosen as the photoanode, and the AuNP/CuBi₂O₄ complex was chosen as the photocathode in photoelectrochemical (PEC) detection. The experiments showed that the constructed self-powered dual-electrode system had a good photoelectric response to white light, and the photocurrent signal of the photocathode was significantly enhanced under the influence of the photoanode. The introduction of G-quadruplex/hemin DNAzyme through aptamer recognition resulted in the generation of insoluble species through catalytic reaction, which led to a significant decrease in the photocurrent, and achieved a highly sensitive detection of the target CEA with a detection limit of 0.021 pg/mL. At the same time, the developed photocathode detection exhibited good selectivity and could effectively avoid interference, making it suitable for real sample analysis. It is expected that this study can facilitate the application of PEC sensors in point-of-care (POC) diagnosis for life analysis.

Graphical Abstract

Self-powered dual-photoelectrode photoelectrochemical aptasensor amplified by hemin/ G-quadruplex-based DNAzyme

To enhance the application performance of graphdiyne (GDY) in electrochemical sensing, carbon nanotubes (CNTs) were grown in situ to construct three-dimensional nanoarchitectures of GDY-CNTs composites. GDY-CNTs showed superior electrochemical properties and detection response to MP when compared with GDY, as the in situ growth of CNTs significantly increased the electrode surface area and enhanced the electron transfer process. GDY-CNTs were successfully used to construct electrochemical sensors for methyl parathion (MP). The proposed sensor exhibited a wide linear relationship for MP ranging from 0.09 to 64.6 µM with a detection limit of 0.05 µM. Moreover, the sensor also showed good stability and acceptable reproducibility, which provided a feasible method for rapid and accurate detection of MP in real samples. This work provides an effective application of graphdiyne in electrochemical sensing with constructed three-dimensional GDY-CNTs.

Graphical Abstract

A point-of-care testing (POCT) assay based on commercial HCG strip was proposed for miRNA21 detection by integrating RCA-HCR cascaded isothermal amplification with CRISPR/Cas12a. Three modules were integrated in the proposed platform: target amplification module composed of rolling circle amplification (RCA) cascaded with hybridization chain reaction (HCR), signal transduction module composed of CRISPR/Cas12a combined with HCG-agarose gel beads probes, and signal readout module composed of commercial HCG strips. The proposed RCA-HCR-CRISPR/Cas12a-HCG strip assay for miRNA21 detection had high sensitivity, and the limit of detection was as low as 37 fM. The proposed assay showed excellent specificity for miRNA21, as other miRNAs did not caused interference for detection. The recoveries of miRNA21 were ranged from 89.0 to 118.0%. The intra-batch and inter-batch coefficient of variation (CV) were 10.1–13.4% and 11.9–14.5%, respectively, which indicated a high accuracy and precision, and the serum matrix did not cause any interference. With the advantages of low-cost, high sensitivity, visualization, and easy popularization, the proposed assay is expected to provide a powerful tool for early diagnosis of tumor disease miRNA, especially in resource-limited areas.

Graphical abstract

An innovative colorimetric sensing strategy was developed for the detection of glucose by the integration of glucose aptamer, glucose oxidase (GOx), and horseradish peroxidase (HRP), termed aptamer proximal enzyme cascade reactions (APECR). In the presence of glucose, aptamer binding enables GOx to catalyze glucose oxidation into H₂O₂ efficiently. Subsequently, the adjacent HRP catalyzes the oxidation of the peroxidase substrate, 2,2′-biazobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS²⁻), utilizing the generated H₂O₂, resulting in a distinct color change. In comparison to the free enzymes and the HRP-GOx system, APECR exhibited higher colorimetric signal. This approach achieved glucose detection within three minutes, which was significantly faster than previous methods. This method showed good sensitivity and selectivity with a limit of detection of 0.013 mM. Moreover, the practical utility of this strategy was verified by achieving rapid detection of glucose in clinical serum samples. Hence, the developed strategy has the advantages of simple operation and rapid analysis time for the detection of glucose in human serum.

Graphical Abstract

A fluorescent aptasensor was developed based on target-induced hairpin conformation switch coupled with nicking enzyme-assisted signal amplification (NESA) to detect the oligomeric form of ß-amyolid peptide (AβO) in cerebrospinal fluid. The hairpin DNA probe (HP) was specifically designed to recognize AβO. When AβO is present in the sensing system, it induces an HP conformational switch and triggers the NESA reaction. After evaluating the parameters of the aptasensor system, we selected Hairpin10, which has a 10-nucleotide extended sequence, as the hairpin sequence that interacts with AβO. The quantitative linear range of the proposed aptasensor is from 11.3 to 113 ng mL⁻¹ in artificial cerebrospinal fluid (aCSF), and the detection limit was 7.29 ng mL⁻¹. The present work realized the assay of AβO in aCSF with satisfactory quantitative results.

Graphical abstract

An exciting upconversion nanoprobe conditioning strategy is proposed to improve the signal-to-background ratio (SBR) through a dye-sensitized strategy, in which the dye functions both as a recognition unit of the detection target and as a sensitizer to amplify the visible luminescence of the lanthanide-doped upconversion nanoparticles (UCNPs), instead of a quencher. The application of this dye-sensitized upconversion nanoprobe to the visual detection of nerve agent mimics diethoxy phosphatidylcholine (DCP) showed excellent detection performance, with up to 110-fold enhancement of the luminescence response of the probe in DCP solution and a detection limit as low as 2 nM. Finally, we performed visual detection of DCP solution and vapor by using test strips containing the probe. It is promising to apply the probe to monitor the leakage of DCP in the real environment.

Graphical abstract

Procalcitonin (PCT) is a reliable biomarker for diagnosing and monitoring bacterial infections and sepsis. PCT exhibits good stability both in vivo and in vitro, and its levels drastically increase in response to bacterial infection or inflammatory reactions in the human body, making it a dependable indicator for sepsis diagnosis and monitoring with significant implications for clinical diagnosis and treatment guidance. Currently, immunosensors are widely utilized in PCT detection due to their high sensitivity and low detection limits. Noble metals, because of their excellent electronic conductivity, biocompatibility, and superior physicochemical properties, are extensively combined with other materials to play a pivotal role in the construction of PCT immunosensors. This review summarizes the research progress on PCT antigen immunosensors based on noble metal composite materials, encompassing the classification and principles of immunosensors. Starting from noble metals, which are widely used as electrode materials in sensors, the review categorizes and discusses the carbon materials, metal oxides, metal sulfides, and other composites with noble metals. The review also elaborates on the influence of sensitive materials on the performance of immunosensors. Finally, the review discusses and anticipates the challenges and future opportunities for the research on PCT antigen immunosensors using noble metal-composite nanomaterials, providing new insights and directions for their application in the treatment and clinical management of sepsis and other diseases.

Graphical Abstract