3D printing (also called "additive manufacturing" or "rapid prototyping") is able to translate computer-aided and designed virtual 3D models into 3D tangible constructs/objects through a ...layer-by-layer deposition approach. Since its introduction, 3D printing has aroused enormous interest among researchers and engineers to understand the fabrication process and composition-structure-property correlation of printed 3D objects and unleash its great potential for application in a variety of industrial sectors. Because of its unique technological advantages, 3D printing can definitely benefit the field of microrobotics and advance the design and development of functional microrobots in a customized manner. This review aims to present a generic overview of 3D printing for functional microrobots. The most applicable 3D printing techniques, with a focus on laser-based printing, are introduced for the 3D microfabrication of microrobots. 3D-printable materials for fabricating microrobots are reviewed in detail, including photopolymers, photo-crosslinkable hydrogels, and cell-laden hydrogels. The representative applications of 3D-printed microrobots with rational designs heretofore give evidence of how these printed microrobots are being exploited in the medical, environmental, and other relevant fields. A future outlook on the 3D printing of microrobots is also provided.
3D printing can enable the customized design and fabrication of microrobots for a wide range of functional applications.
Molecular imprinting technology (MIT), often described as a method of making a molecular lock to match a molecular key, is a technique for the creation of molecularly imprinted polymers (MIPs) with ...tailor-made binding sites complementary to the template molecules in shape, size and functional groups. Owing to their unique features of structure predictability, recognition specificity and application universality, MIPs have found a wide range of applications in various fields. Herein, we propose to comprehensively review the recent advances in molecular imprinting including versatile perspectives and applications, concerning novel preparation technologies and strategies of MIT, and highlight the applications of MIPs. The fundamentals of MIPs involving essential elements, preparation procedures and characterization methods are briefly outlined. Smart MIT for MIPs is especially highlighted including ingenious MIT (surface imprinting, nanoimprinting,
etc.
), special strategies of MIT (dummy imprinting, segment imprinting,
etc.
) and stimuli-responsive MIT (single/dual/multi-responsive technology). By virtue of smart MIT, new formatted MIPs gain popularity for versatile applications, including sample pretreatment/chromatographic separation (solid phase extraction, monolithic column chromatography,
etc.
) and chemical/biological sensing (electrochemical sensing, fluorescence sensing,
etc.
). Finally, we propose the remaining challenges and future perspectives to accelerate the development of MIT, and to utilize it for further developing versatile MIPs with a wide range of applications (650 references).
This critical review presents a survey of recent developments in technologies and strategies for the preparation of MIPs, followed by the application of MIPs in sample pretreatment, chromatographic separation and chemical sensing.
High performance photodetectors play important roles in the development of innovative technologies in many fields, including medicine, display and imaging, military, optical communication, ...environment monitoring, security check, scientific research and industrial processing control. Graphene, the most fascinating two‐dimensional material, has demonstrated promising applications in various types of photodetectors from terahertz to ultraviolet, due to its ultrahigh carrier mobility and light absorption in broad wavelength range. Graphene field effect transistors are recognized as a type of excellent transducers for photodetection thanks to the inherent amplification function of the transistors, the feasibility of miniaturization and the unique properties of graphene. In this review, we will introduce the applications of graphene transistors as photodetectors in different wavelength ranges including terahertz, infrared, visible, and ultraviolet, focusing on the device design, physics and photosensitive performance. Since the device properties are closely related to the quality of graphene, the devices based on graphene prepared with different methods will be addressed separately with a view to demonstrating more clearly their advantages and shortcomings in practical applications. It is expected that highly sensitive photodetectors based on graphene transistors will find important applications in many emerging areas especially flexible, wearable, printable or transparent electronics and high frequency communications.
Graphene demonstrates promising applications in various types of photodetectors from terahertz to ultraviolet, due to its ultrahigh carrier mobility and light absorption in a broad wavelength range. Graphene field effect transistors are recognized as a type of excellent transducers for photodetection thanks to the inherent amplification function of the transistors, the feasibility of miniaturization, and the unique properties of graphene.
•The unique optical properties of nanomaterials made them candidates in the design of optical sensors.•The review summarized the design principles of nanomaterials-based optical sensors for Hg2+ ...detection.•Three kinds of optical nanosensors were included colorimetric assay, fluorometric analysis and SERS detection.
As one of the most toxic heavy metals, mercury ion (Hg2+) has become a concern focus for its severe threats to environment and human health. As a result, it is of great importance to develop novel methods to realize the recognition and quantification of Hg2+. The past decades witness the development of nanomaterial-based optical sensors for Hg2+ detection, showing the benefits of simplicity, rapidity, high sensitivity and selectivity, and cost-effectiveness. The reported methods have allowed the detectability down to nanomolar concentrations or much lower levels, and proved their practical applications for detecting and quantifying Hg2+ in synthetic solutions or natural water samples. In this review, we summarize the published innovations in nanomaterial-based optical sensors for the detection of Hg2+ according to different sensing strategies, including colorimetric, fluorescent and surface enhanced Raman scattering detection. Moreover, some challenges and significant attempts related to these methods are also discussed.
Molecular imprinting-based solid-phase extraction (MI-SPE) has been in the spotlight to improve the recognition selectivity and detection sensitivity. MI-SPE provides a powerful tool for ...chemo/bioanalysis in complex matrices and meanwhile, benefits from distinguished advantages such as easy operation, high throughput, low cost, high selectivity and durability. This review proposed the recent advances in molecular imprinting concerning novel preparation strategies of molecularly imprinted polymers (MIPs) and typical applications of MI-SPE. Preparation strategies are highlighted by dividing into ten sections mainly including dummy imprinting, multi-template imprinting, surface imprinting, water-compatible imprinting, restricted access material combining imprinting etc.; each section provides the descriptions about what restrictions led to the emergence of any strategy, strengths/weaknesses of every strategy and universal applications of upgraded MIPs in various SPE modes prior to chromatographic analysis. The potential of MIPs for implementation in routine laboratory activities and scale-up is expected, and finally remaining challenges and future perspectives are proposed.
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•Current challenges on MIPs and related imprinting strategies are comprehensively summarized.•Applications of upgraded molecular imprinting based solid-phase extraction are discussed.•The potential of MIPs for implementation in routine laboratory activities and scale-up is summarized.•The future study requirements are highlighted.
One pressing concern today is to construct sensors that can withstand various disturbances for highly selective and sensitive detecting trace analytes in complicated samples. Molecularly imprinted ...polymers (MIPs) with tailor-made binding sites are preferred to be recognition elements in sensors for effective targets detection, and fluorescence measurement assists in highly sensitive detection and user-friendly control. Accordingly, molecular imprinting-based fluorescence sensors (MI-FL sensors) have attracted great research interest in many fields such as chemical and biological analysis. Herein, we comprehensively review the recent advances in MI-FL sensors construction and applications, giving insights on sensing principles and signal transduction mechanisms, focusing on general construction strategies for intrinsically fluorescent or nonfluorescent analytes and improvement strategies in sensing performance, particularly in sensitivity. Construction strategies are well overviewed, mainly including the traditional indirect methods of competitive binding against pre-bound fluorescent indicators, employment of fluorescent functional monomers and embedding of fluorescence substances, and novel rational designs of hierarchical architecture (core-shell/hollow and mesoporous structures), post-imprinting modification, and ratiometric fluorescence detection. Furthermore, MI-FL sensor based microdevices are discussed, involving micromotors, test strips and microfluidics, which are more portable for rapid point-of-care detection and in-field diagnosing. Finally, the current challenges and future perspectives of MI-FL sensors are proposed.
•Molecular imprinting based fluorescence sensors (MI-FL sensors) are reviewed.•Sensing principle and signal transduction mechanisms are introduced.•General and novel construction strategies for MI-FL sensors are summarized.•MI-FL sensor based microdevices are overviewed.•The present challenges and perspectives of MI-FL sensors are proposed.
Current status and challenges of ion imprinting Fu, Junqing; Chen, Lingxin; Li, Jinhua ...
Journal of materials chemistry. A, Materials for energy and sustainability,
01/2015, Letnik:
3, Številka:
26
Journal Article
Recenzirano
Odprti dostop
Ion imprinting technology (IIT) aims to recognize ions while retaining the unique virtues of molecular imprinting technology (MIT), namely structure predictability, recognition specificity and ...application universality. Owing to special coordination or electrostatic interactions, ion imprinted polymers (IIPs) are generally compatible with aqueous media and have advantages over most molecularly imprinted polymers (MIPs). IIPs can achieve effective identification of water-soluble ions, especially heavy metals and radioactive elements that cause increasing concerns. The purpose of this review is to summarize recent advances of ion imprinting, focusing on the current status and challenges in fundamentals and applications that involve almost all types of ions and ion-related molecular imprinting. In addition, various smart strategies are highlighted, such as surface imprinting, stimuli-responsive imprinting, dual/multiple components imprinting, click chemistry, and microwave-assisted heating. In this review, the elemental periodic table is first utilized as a template to introduce ion classification standards for various IIPs, including main groups, transition elements, actinides, rare earths, metalloids, anion imprinting and secondary imprinting. Finally, the challenges and possible solution strategies plus future trends are also proposed (302 references).
The current status of ion imprinting, the applications, the challenges and future trends are comprehensively reviewed.
A novel green synthesis strategy was proposed for preparation of multitemplate molecularly imprinted biopolymers (mt-MIBP) in aqueous media with less consumption of organic solvents, which were ...subsequently used as sorbents of ultrasound-assisted dispersive solid-phase extraction (d-SPE) for simultaneous recognition and efficient separation of B-family vitamins in juice samples, followed by high performance liquid chromatography (HPLC) determination. The obtained mt-MIBP was fully characterized by SEM, FT-IR, TEM, and BET. It offered high binding capacity, good selectivity, and fast dynamics toward all the templates. Involved parameters in the d-SPE efficiency such as mt-MIBP mass, sonication time, and eluting/washing solvents’ types and volumes were concurrently investigated by central composite design with rapidity and reliability. Under the optimum conditions, the developed mt-MIBP-d-SPE-HPLC method exhibited wide linear range, low limits of detection and quantification (LOQs) within 1.2–5.5 μg L–1 and 4.0–18.4 μg L–1, respectively, and appropriate repeatability (relative standard deviation values below 4.2%, n = 4). The high selectivity of this method makes it suitable for successful monitoring of vitamins in juice samples with satisfactory recoveries of 75.8–92.7%, 81.1–92.5%, and 84.7–93.8% for vitamins riboflavin (B2), nicotinamide (B3), and pyridoxine (B6), respectively. The present study implied highly promising perspectives of water-compatible eco-friendly mt-MIBP for highly effective multiresidue analysis in complicated matrixes.
The speciation analysis of heavy metal pollutants is very important because different species induce different toxicological effects. Nanomaterial-assisted optical sensors have achieved rapid ...developments, displaying wide applications to heavy metal ions but few to metal speciation analysis. In this work, a novel colorimetric nanosensor strategy for mercury speciation was proposed for the first time, based on the analyte-induced aggregation of gold nanoparticles (Au NPs) with the assistance of a thiol-containing ligand of diethyldithiocarbamate (DDTC). Upon the addition of mercury species, because Hg-DDTC was more stable than Cu-DDTC, a place-displacement between Hg species and Cu2+ would occur, and thereby the functionalized Au NPs would aggregate, resulting in a color change. Moreover, by virtue of the masking effect of ethylenediaminetetraacetic acid (EDTA), the nanosensor could readily discriminate organic mercury and inorganic mercury (Hg2+), and it is thus anticipated to shed some light on the colorimetric sensing of organic mercury. So, a direct, simple colorimetric assay for selective determination of Hg species was obtained, presenting high detectability, such as up to 10 nM for Hg2+ and 15 nM for methylmercury. Meanwhile, the strategy offered excellent selectivity toward mercury species against other metal ions. The simple, rapid, and sensitive label-free colorimetric sensor for the determination of Hg species provided an attractive alternative to conventional methods, which usually involve sophisticated instruments, complicated processes, and long periods of time. More importantly, by using mercury as a model, an excellent nanomaterial-based optical sensing platform can be developed for speciation analysis of trace heavy metals, which can lead to nanomaterials stability change through smart functionalization and reasonable interactions.
Micrometeorite impacts and solar wind irradiation, the dominant space weathering (SW) processes, largely modified compositions and microtexture of soil materials on the Moon. Here, we report the SW ...characteristics of the Chang'e‐5 lunar soils from mid‐high latitude (43.06°N). All mineral phases exposed on the surface of a single basalt clast have a vapor deposit layer, whereas the textures of the solar wind irradiation‐damaged zone are dependent on the host mineral species. Nanophase Fe (npFe0) particles are spherical in the amorphized zone of pyroxenes, elongated in ilmenite, and irregular on the jagged surface of iron sulfide, but not found in Fe‐poor merrillite. Vesicles were found in the damaged zone of ilmenite and merrillite, but with different shapes. The observations were compared to Apollo samples and demonstrate no significant altitude‐dependent effects on the SW, which is important for decoding the reflectance spectra of the Moon.
Plain Language Summary
The lunar surface has been suffering intense meteorite impacts and solar wind irradiation for billions of years, which heavily modifies its physical properties, chemical compositions and mineralogical features, and in turn, the optical reflectance spectra of the Moon. The meteorite impacts are random events, but the intensity of solar wind irradiation is latitude dependent. However, all Apollo and Luna missions landed in a narrow and low range of lunar latitude. The Chang'e‐5 (CE‐5) mission returned lunar soil samples from a middle latitude (43.06°N), providing unique samples for study of lunar space weathering (SW). In this paper, we report the SW features of various minerals from a single basaltic clast of the CE‐5 sample. Our observations reveal phase‐dependent effects on the SW. Furthermore, the CE‐5 lunar soil shows no significant differences from those of Apollo samples, suggestive of little latitude‐dependent effects on lunar SW.
Key Points
The space weathering (SW) characteristics of lunar soils returned by Chang'e‐5 landing at the mid‐high latitude site are reported
Microscopic textures of SW depend on mineral species but show no relationship with the latitude of sampling site
The SW products by micrometeorite impacts and solar wind irradiation are distinguished
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