Unlocking the Power of Nanopores: Recent Advances in Biosensing Applications and Analog Front-End

Nanopores for DNA and biomolecule analysis: Diagnostic, genomic insights, applications in energy conversion and catalysis

Recently, nanopores have emerged as highly significant structures with broad applications in diverse scientific and technological fields. They can naturally occur in biological membranes or be artificially fabricated using advanced techniques. Recent advances in nanopore technology have revolutionized genomics by offering previously unheard-of capacities for deoxyribo nucleic acid (DNA) sequencing and analysis. These tiny pores allow individual molecules to be found more easily, allowing for real-time DNA analysis and providing currently unheard-of insights into genetics and diagnostics. By tracking alterations in electrical or ionic currents as biomolecules traverse the pore, nanopores make possible the real-time recognition of other biomolecules, like proteins, nucleic acids, and small molecules, eliminating the need for labeling. This label-free detection potential holds a huge promise in medical diagnostics, genotyping, environmental monitoring, etc. Nanopores have significantly improved DNA sequencing technology such as increment in read length, enabling researchers to sequence entire genomic regions, accuracy can be improved and recent updates have led to a reported increase in total DNA reads, demonstrating the technology's capacity for high-throughput applications via trapping individual DNA strands and monitoring the variations of ionic current as each nucleotide passes across the pore. Finally, nanopore sequencing is well-known as a novel and highly flexible technique for DNA analyses, which has a huge deal of promise in clinical diagnosis and genomics research. Hence, this review article comprehensively explains nanopores for DNA analysis and other biomolecules, their synthesis, and diverse applications.

Nanopipettes as a Potential Diagnostic Tool for Selective Nanopore Detection of Biomolecules

Nanopipettes, as a class of solid-state nanopores, have evolved into universal tools in biomedicine for the detection of biomarkers and different biological analytes. Nanopipette-based methods combine high sensitivity, selectivity, single-molecule resolution, and multifunctionality. The features have significantly expanded interest in their applications for the biomolecular detection, imaging, and molecular diagnostics of real samples. Moreover, the ease of manufacturing nanopipettes, coupled with their compatibility with fluorescence and electrochemical methods, makes them ideal for portable point-of-care diagnostic devices. This review summarized the latest progress in nanopipette-based nanopore technology for the detection of biomarkers, DNA, RNA, proteins, and peptides, in particular β-amyloid or α-synuclein, emphasizing the impact of technology on molecular diagnostics. By addressing key challenges in single-molecule detection and expanding applications in diverse biological areas, nanopipettes are poised to play a transformative role in the future of personalized medicine.

Unlocking cell surface enzymes: A review of chemical strategies for detecting enzymatic activity

BACKGROUND

Cell surface enzymes are important proteins that play essential roles in controlling a wide variety of biological processes, such as cell-cell adhesion, recognition and communication. Dysregulation of enzyme-catalyzed processes is known to contribute to numerous diseases, including cancer, cardiovascular diseases and neurodegenerative disease. From the perspective of drug discovery and development, there is a growing interest in detecting the cell surface enzyme activity, propelled by the arising need for innovative diagnostic and therapeutic approaches to address various health conditions.

RESULTS

In this review, we focus on advances in chemical strategies for the detection of cell surface enzyme activity. Firstly, this comprehensive review delves into the diverse landscape of cell surface enzymes, detailing their structural features and diverse biological functions. Various enzyme families on the cell surface are examined in depth, elucidating their roles in cellular homeostasis and signaling cascades. Subsequently, various biosensors, including electrochemical biosensors, optical biosensors and dual-mode biosensors, used for detecting the cell surface enzyme activity are described. Exemplars are provided to illustrate the mechanisms, limit of detection and prospective applications of these different biosensors. Furthermore, this review unravels the intricate interplay between cell surface enzymes and cellular physiology, contributing to the development of novel diagnostic and therapeutic strategies for various diseases. In the end, the review provides insights into the ongoing challenges and future prospects associated with the detection of cell surface enzyme activity.

SIGNIFICANCE

Detecting cell surface enzyme activity holds pivotal significance in biomedical research, offering valuable insights into cellular physiology and disease pathology. Understanding enzyme activity aids in elucidating signaling pathways, drug interactions and disease mechanisms. This knowledge informs the development of diagnostic tools and therapeutic interventions targeting various ailments, from cancer to neurodegenerative disease. Additionally, it contributes to the advancement of drug screening and personalized medicine approaches.

Expanding the Role of Chiral Drugs and Chiral Nanomaterials as a Potential Therapeutic Tool

Chirality, the property of molecules having mirror-image forms, plays a crucial role in pharmaceutical and biomedical research. This review highlights its growing importance, emphasizing how chiral drugs and nanomaterials impact drug effectiveness, safety, and diagnostics. Chiral molecules serve as precise diagnostic tools, aiding in accurate disease detection through unique biomolecule interactions. The article extensively covers chiral drug applications in treating cardiovascular diseases, CNS disorders, local anesthesia, anti-inflammatories, antimicrobials, and anticancer drugs. Additionally, it explores the emerging field of chiral nanomaterials, highlighting their suitability for biomedical applications in diagnostics and therapeutics, enhancing medical treatments.

Interface Water Assists in Dimethyl Sulfoxide Crossing and Poration in Model Bilayer

Understanding the mechanism of transport and pore formation by a commonly used cryoprotectant, dimethyl sulfoxide (DMSO), across cell membranes is fundamentally crucial for drug delivery and cryopreservation. To shed light on the mechanism and thermodynamics of pore formation and crossing behavior of DMSO, extensive all-atom molecular dynamics simulations of 1,2-dimyristoyl-rac-glycero-3-phosphocholine (DMPC) bilayers are performed at various concentrations of DMSO at a temperature above the physiological temperature. Our results unveil that DMSO partially depletes water from the interface and positions itself between lipid heads without full dehydration. This induces a larger area per headgroup, increased disorder, and enhanced fluidity without any disintegration even at the highest DMSO concentration studied. The enhanced disorder fosters local fluctuations at the interface that nucleate dynamic and transient pores. The potential of mean force (PMF) of DMSO crossing is derived from two types of biased simulations: a single DMSO pulling using the umbrella sampling technique and a cylindrical pore formation using the recently developed chain reaction coordinate method. In both cases, DMSO crossing encounters a barrier attributed to unfavorable polar nonpolar interactions between DMSO and lipid tails. As the DMSO concentration increases, the barrier height reduces along with the faster lateral and perpendicular diffusion of DMSO suggesting favorable permeation. Our findings suggest that the energy required for pore formation decreases when water assists in the formation of DMSO pores. Although DMSO displaces water from the interface toward the far interface region without complete dehydration, the presence of interface water diminishes pore formation free energy. The existence of interface water leads to the formation of a two-dimensional percolated water-DMSO structure at the interface, which is absent otherwise. Overall, these insights into the mechanism of DMSO crossing and pore formation in the bilayer will contribute to understanding cryoprotectant behavior under supercooled conditions in the future.