With reduced background and high sensitivity, photoelectrochemistry (PEC) may be applied as an intracellular nanotool and open a new technological direction of single‐cell study. Nevertheless, the ...present palette of single‐cell tools lacks such a PEC‐oriented solution. Here a dual‐functional photocathodic single‐cell nanotool capable of direct electroosmotic intracellular drug delivery and evaluation of oxidative stress is devised by engineering a target‐specific organic molecule/NiO/Ni film at the tip of a nanopipette. Specifically, the organic molecule probe serves simultaneously as the biorecognition element and sensitizer to synergize with p‐type NiO. Upon intracellular delivery at picoliter level, the oxidative stress effect will cause structural change of the organic probe, switching its optical absorption and altering the cathodic response. This work has revealed the potential of PEC single‐cell nanotool and extended the boundary of current single‐cell electroanalysis.
An integrated photocathodic nanotool was fabricated for dual‐functional intracellular drug delivery and evaluation of cellular oxidative stress in single live cell.
Rational utilization of the rich light‐bio‐matter interplay taking place in single‐cell analysis represents a new technological direction in the field. The light‐fueled operation is expected to ...achieve advanced photoelectrochemical (PEC) single‐cell analysis with unknown possibilities. Here, a PEC nanoreactor capable of single‐cell sampling and near zero‐background Faradaic detection of intracellular microRNA (miR) is devised by the construction of a small reaction chamber accommodating the target‐triggered hybridization chain reaction for binding the metallointercalator of Ru(bpy)2(dppz)2+ as the signal reporter. Light stimulation of the dsDNA/metallointercalator adduct will induce the generation of photocurrents, underpinning a zero‐biased and near zero‐background PEC method toward Faradaic detection of non‐electrogenic miR at the single‐cell level. Using this nanotool, lower miR concentration in the near‐nucleus region than that in the main cytosol was revealed.
A photoelectrochemical nanoreactor was devised for single‐cell sampling and near zero‐background faradic detection of intracellular microRNA. This platform provided a new perspective for exploring light‐biomatter interplay toward single‐cell studies.
Single‐cell epigenetics is envisioned to decipher manifold epigenetic phenomena and to contribute to our accurate knowledge about basic epigenetic mechanisms. Engineered nanopipette technology has ...gained momentum in single‐cell studies; however, solutions to epigenetic questions remain unachieved. This study addresses the challenge by exploring N6‐methyladenine (m6A)‐bearing deoxyribozyme (DNAzyme) confined within a nanopipette for profiling a representative m6A‐modifying enzyme, fat mass and obesity‐associated protein (FTO). Electroosmotic intracellular extraction of FTO could remove the m6A and cause DNAzyme cleavage, leading to the altered ionic current signal. Because the cleavage can release a DNA sequence, we simultaneously program it as an antisense strand against FTO‐mRNA, intracellular injection of which has been shown to induce early stage apoptosis. This nanotool thus features the dual functions of studying single‐cell epigenetics and programmable gene regulation.
An integrated iontronic nanotool was developed for the study of single‐cell epigenetics and programmable gene regulation. With the nanotool, an N6‐methyladenine (m6A)‐modified deoxyribozyme (DNAzyme) was used for profiling a representative m6 A‐modifying enzyme, fat mass and obesity‐associated protein (FTO), which also released a DNA sequence that could be programmed as an antisense strand against intracellular FTO‐mRNA.
Though significant advances are made in the arena of single‐cell electroanalysis, quantification of intracellular amino acids of human cells remains unsolved. Exemplified by l‐histidine (l‐His), this ...issue is addressed by a practical electrochemical nanotool synergizing the highly accessible nanopipette with commercially available synthetic DNAzyme. The fabricated nanotools are screened before operation of a single‐use manner, and the l‐His‐provoked cleavage of the DNA molecules can be sensibly transduced by the ionic current rectification response, the intrinsic property of nanopipette governed by its interior surface charges. Regional distribution of cytosolic l‐His level in human cells is electrochemically quantified for the first time, and time‐dependent drug treatment effects are further revealed. This work unveils the possibility of electrochemistry for quantification of cytosolic amino acids of a spatial‐ and time‐based manner and ultimately enables a better understanding of amino acid‐involved events in living cells.
The solution‐to‐electrochemical single‐cell analysis of intracellular amino acids is achieved by integrating nanopipette with specific DNAzyme and exemplified by targeting l‐histidine. It allowed minimally invasive detection with high sensitivity and selectivity. Drug treatment is also probed of a spatial‐ and time‐based manner.
Single‐cell protein therapeutics is expected to promote our in‐depth understanding of how a specific protein with a therapeutic dosage treats the cell without population averaging. However, it has ...not yet been tackled by current single‐cell nanotools. We address this challenge by the use of a double‐barrel nanopipette, in which one lumen was used for electroosmotic cytosolic protein delivery and the other was customized for ionic evaluation of the consequence. Upon injection of protein DJ‐1 through the delivery lumen, upregulation of the antioxidant protein could protect neural PC‐12 cells against oxidative stress from phorbol myristate acetate exposure, as deduced by targeting of the cytosolic hydrogen peroxide by the detecting lumen. The nanotool developed in this study for single‐cell protein therapeutics provides a perspective for future single‐cell therapeutics involving different therapeutic modalities, such as peptides, enzymes and nucleic acids.
Electrochemical single‐cell protein therapeutics was devised with an engineered θ‐nanopipette and exemplified by protein DJ‐1 enabled neuroprotection. Upon DJ‐1 injection through the delivery lumen, upregulation of the antioxidant protein could protect neural PC‐12 cells against oxidative stress from phorbol myristate acetate exposure, as deduced by targeting of the cytosolic H2O2 by the detecting lumen.
Carbon materials, including graphite, hard carbon, soft carbon, graphene, and carbon nanotubes, are widely used as high‐performance negative electrodes for sodium‐ion and potassium‐ion batteries ...(SIBs and PIBs). Compared with other materials, carbon materials are abundant, low‐cost, and environmentally friendly, and have excellent electrochemical properties, which make them especially suitable for negative electrode materials of SIBs and PIBs. Compared with traditional carbon materials, modifications of the morphology and size of nanomaterials represent effective strategies to improve the quality of electrode materials. Different nanostructures make different contributions toward improving the electrochemical performance of electrode materials, so the synthesis of nanomaterials is promising for controlling the morphology and size of electrode materials. This paper reviews the progress made and challenges in the use of carbon materials as negative electrode materials for SIBs and PIBs in recent years. The differences in Na+ and K+ storage mechanisms among different types of carbon materials are emphasized.
Carbon materials represent one of the most promising candidates for negative electrode materials of sodium‐ion and potassium‐ion batteries (SIBs and PIBs). This review focuses on the research progress of carbon materials such as graphite, hard carbon, soft carbon, graphene and carbon nanotubes, and other carbon nanomaterials as negative electrode materials for SIBs and PIBs.
Portable and wearable electronic devices are human-centered devices; therefore, many unique attributes are highly desirable, such as flexibility, being self-powered, and waterproof. These properties ...render devices excellent adaptivity in harsh operation environments. In this work, we report an integrated triboelectric tactile sensor array with flexible, transparent, self-powered, and waterproof features. Each tactile sensor is a surface nano/microtexture enhanced triboelectric nanogenerator. The sensor array can serve as a touch panel for electronic devices. Owing to a unique design of a built-in triboelectric contact pair and an electrical shielding layer, an individual pixel of the fabricated tactile sensor array can generate an open circuit voltage up to 1.613 V and a short circuit current density of 47.308 mA/m2 under 612.5 kPa. The tactile sensors can produce stable voltage signals regardless of the materials of the touching objects, and work stably both in ambient and aqueous environments. To examine the touch panel function of a sensor array, a matrix of 10 × 10 individually addressable 4 mm × 4 mm triboelectric sensors has been integrated into a thin, transparent, and flexible film, and the 2-D touch mapping has been successfully demonstrated. The unique triboelectric tactile sensor array reported here is robust and highly versatile, and it may find broad applications in display, wearable electronics, artificial skins, Internet of Things (IoT), etc.
This work proposes the concept of single‐cell microRNA (miR) therapy and proof‐of‐concept by engineering a nanopipette for high‐precision miR‐21‐targeted therapy in a single HeLa cell with sensitive ...photoelectrochemical (PEC) feedback. Targeting the representative oncogenic miR‐21, the as‐functionalized nanopipette permits direct intracellular drug administration with precisely controllable dosages, and the corresponding therapeutic effects can be sensitively transduced by a PEC sensing interface that selectively responds to the indicator level of cytosolic caspase‐3. The experimental results reveal that injection of ca. 4.4 × 10−20 mol miR‐21 inhibitor, i.e., 26488 copies, can cause the obvious therapeutic action in the targeted cell. This work features a solution to obtain the accurate knowledge of how a certain miR‐drug with specific dosages treats the cells and thus provides an insight into futuristic high‐precision clinical miR therapy using personalized medicine, provided that the prerequisite single‐cell experiments are courses of personalized customization.
The concept of high‐precision single‐cell microRNA therapy is proposed and devised by a functional nanopipette, which allows precise miR‐21 inhibitor delivery to induce cell apoptosis and responds selectively to caspase‐3 of a sensitive photoelectrochemical feedback. It can reveal what the precise drug amount can cause the effective therapeutic action.
Photonic (bio)electronic circuits and devices have been an enduring goal in modern photonics and electronics. Organic photoelectrochemical transistor (OPECT) interfacing light with biological world ...creates a substantial opportunity to this end due to the immense light−bio−matter interplay. Through modulating the invisible ionic circuit of organic electrochemical transistor (OECT) with a bipolar electrode (BPE) accommodating different semiconductor combinations, the unique photonic electronics toward logic and sensor applications are realized. Six combinations of BPEs are produced by the representative n‐type CdS/TiO2 and p‐type BiOI/NiO semiconductors, and the corresponding photonic characteristics and operation rationale are systematically investigated and explained. Designation of opto‐logic circuits and feasibility as a sensory platform are subsequently demonstrated. This work not only represents new photonic bioelectronics but also provides a generic mechanism for the design and development of advanced opto‐logics and bio‐analytics.
The ionic circuit of organic electrochemical transistor (OECT) is rationally modulated with bipolar electrode accommodating specific photoelectrochemical processes to realize photonic OECT with unique transfer characteristics and transient behaviors. The as‐developed optoelectronics can be applied as a generic and extensible platform for designation of new opto‐logic circuits and bio‐sensory systems.
High Resolution Transmission Electron Microscopy (HRTEM) and Molecular Dynamics (MD) simulations were conducted here to study the plastic deformation induced γ (fcc)→ε (hcp)→α′ (bcc) martensitic ...transformation in 304 stainless steels for the α′ nucleation from single hcp-ε laths. Results elucidate that the underlying microscopic mechanism for the α′ nucleation from single hcp-ε laths obeys the Bogers–Burgers–Olson–Cohen “3T/8–T/3” model. In particular, the atomic-scale observations clearly show the Kurdyumov–Sachs (K–S) lattice orientation relation (OR) and Pitsch OR at the γ/α′ interfaces, the lattice rotation inside an α′ martensitic inclusion, the transition lattice and the reverse shear-shuffling induced continuous lattice elastic deformation at the diffuse ε/α′ interface, which caters the 3T/8 and T/3 shears and sheds atomic process insight into the mechanism of the martensitic transformation.
