Extracellularly Detectable Electrochemical Signals of Living Cells Originate from Metabolic Reactions

Recent advances in electrochemical cell-based biosensors for food analysis: Strategies for sensor construction

Owing to their advantages such as great specificity, sensitivity, rapidity, and possibility of noninvasive and real-time monitoring, electrochemical cell-based biosensors (ECBBs) have been a powerful tool for food analysis encompassing the areas of nutrition, flavor, and safety. Notably, the distinctive biological relevance of ECBBs enables them to mimic physiological environments and reflect cellular behaviors, leading to valuable insights into the biological function of target components in food. Compared with previous reviews, this review fills the current gap in the narrative of ECBB construction strategies. The review commences by providing an overview of the materials and configuration of ECBBs, including cell types, cell immobilization strategies, electrode modification materials, and electrochemical sensing types. Subsequently, a detailed discussion is presented on the fabrication strategies of ECBBs in food analysis applications, which are categorized based on distinct signal sources. Lastly, we summarize the merits, drawbacks, and application scope of these diverse strategies, and discuss the current challenges and future perspectives of ECBBs. Consequently, this review provides guidance for the design of ECBBs with specific functions and promotes the application of ECBBs in food analysis.

Supramolecular host-guest interaction triggered dye extraction from metal-organic framework for dual-mode ATP sensing from serum

Adenosine triphosphate (ATP) universally exists in all living organisms and holds a paramount role as a fundamental energy molecule in daily life. The abnormal concentration of ATP is closely related to many diseases, making the highly efficient detection of ATP very urgent. In this study, a dual-mode sensing system was developed to detect ATP sensitively and selectively via both DPV and fluorescence (FL) techniques, based on the strong interaction of ATP and Zn (II) nodes of zeolitic imidazolate framework-90 (ZIF-90). The disassembly of ZIF-90 further induced the subsequent release of pre-loaded rhodamine B (RhB). Benefitting from the robust host-guest recognition of β-cyclodextrin (β-CD) towards RhB, an enzyme-free and highly specific DPV detection strategy was established with the linear detecting range of 10.0-1.0 × 108 pM and the limit of detection (LOD) as low as 0.13 pM. Meanwhile, the FL sensing mode based on RhB exhibits comparable sensing performance with the linearity range of 10.0-1.0 × 107 pM and the LOD of 0.29 pM. Furthermore, the enzyme-free ATP sensing system exhibit outstanding long-term storage stability. The two-mode sensing platform was successfully applied to detect the ATP in human serum samples with the yielded result highly agree with the results of commercial ELISA kits. This dual-mode sensing platform is inspiring and paves the road for developing high-performance biosensor, demonstrating enormous potential for vitro diagnosis and practice clinic.

Recent Advances in Electrochemical Detection of Cell Energy Metabolism

Cell energy metabolism is a complex and multifaceted process by which some of the most important nutrients, particularly glucose and other sugars, are transformed into energy. This complexity is a result of dynamic interactions between multiple components, including ions, metabolic intermediates, and products that arise from biochemical reactions, such as glycolysis and mitochondrial oxidative phosphorylation (OXPHOS), the two main metabolic pathways that provide adenosine triphosphate (ATP), the main source of chemical energy driving various physiological activities. Impaired cell energy metabolism and perturbations or dysfunctions in associated metabolites are frequently implicated in numerous diseases, such as diabetes, cancer, and neurodegenerative and cardiovascular disorders. As a result, altered metabolites hold value as potential disease biomarkers. Electrochemical biosensors are attractive devices for the early diagnosis of many diseases and disorders based on biomarkers due to their advantages of efficiency, simplicity, low cost, high sensitivity, and high selectivity in the detection of anomalies in cellular energy metabolism, including key metabolites involved in glycolysis and mitochondrial processes, such as glucose, lactate, nicotinamide adenine dinucleotide (NADH), reactive oxygen species (ROS), glutamate, and ATP, both in vivo and in vitro. This paper offers a detailed examination of electrochemical biosensors for the detection of glycolytic and mitochondrial metabolites, along with their many applications in cell chips and wearable sensors.

Progress in Nano-Biosensors for Non-Invasive Monitoring of Stem Cell Differentiation

Non-invasive, non-destructive, and label-free sensing techniques are required to monitor real-time stem cell differentiation. However, conventional analysis methods, such as immunocytochemistry, polymerase chain reaction, and Western blot, involve invasive processes and are complicated and time-consuming. Unlike traditional cellular sensing methods, electrochemical and optical sensing techniques allow non-invasive qualitative identification of cellular phenotypes and quantitative analysis of stem cell differentiation. In addition, various nano- and micromaterials with cell-friendly properties can greatly improve the performance of existing sensors. This review focuses on nano- and micromaterials that have been reported to improve sensing capabilities, including sensitivity and selectivity, of biosensors towards target analytes associated with specific stem cell differentiation. The information presented aims to motivate further research into nano-and micromaterials with advantageous properties for developing or improving existing nano-biosensors to achieve the practical evaluation of stem cell differentiation and efficient stem cell-based therapies.