An intelligent ratiometric fluorescent assay based on MOF nanozyme-mediated tandem catalysis that guided by contrary logic circuit for highly sensitive sarcosine detection and smartphone-based portable sensing application.

As the well-known test-indicator for early prostate cancer (PCa), sarcosine (SA) is closely related to the differential pathological process, which makes its accurate determination increasingly significant. Herein, we for the first time expanded the peroxidase (POD)-like property of facile-synthesized Zn-TCPP(Fe) MOF to fluorescent substrates and exploited it to ratiometric fluorescent (RF) sensing. By harnessing the effective catalytic oxidation of MOF nanozyme toward two fluorescent substrates (Scopoletin, SC; Amplex Red, AR) with contrary changes, and target-responsive (SA + SOx)/MOF/(SC + AR) tandem catalytic reaction, we constructed the first MOF nanozyme-based RF sensor for the quantitative determination of SA.

A facile, low-cost bimetallic iron-nickel MOF nanozyme-propelled ratiometric fluorescent sensor for highly sensitive and selective uric acid detection and its smartphone application.

As a kind of well-known disease biomarker, uric acid (UA) is closely associated with normal metabolism and health. Despite versatile nanozymes facilitating the analysis of UA, most previous works could only generate single-signal outputs with unsatisfactory detection performance. Exploring a novel ratiometric fluorescent UA sensor with high sensitivity, reliability and portable sensing ability based on facile, low-cost nanozymes is still challenging.

A cost-effective, "mix & act" G-quadruplex/Cu (II) metal-nanozyme-based ratiometric fluorescent platform for highly sensitive and selective cysteine/bleomycin detection and multilevel contrary logic computing.

Versatile nanozymes with fascinating catalytic properties provide inspiring and effective options for biosensing and pharmaceutical analysis. Herein, we report the first nanozyme-based ratiometric fluorescent platform for cysteine (Cys) and bleomycin (BLM) detection by harnessing the cost-effective and "mix & act" G-quadruplex/Cu(II) (G4/Cu) metal-nanozyme with satisfactory peroxidase-like activity, which was fully proven by circular dichroism (CD), electron paramagnetic resonance (EPR) spectra and reactive oxygen species (ROS) scavenging experiments. Based on the catalytic oxidation of G4/Cu metal-nanozyme toward two fluorescent substrates (Amplex Ultrared, AU; Scopoletin, Sc) with opposite responses in the presence of HO, and the specific interaction between Cu and targets, we achieved the highly sensitive detection of Cys and BLM.

Toward Minute-Level DNA Computing: An Ultrafast, Cost-Effective, and Universal System for Lighting Up Various Concurrent DNA Logic Nanodevices (CDLNs) and Concatenated Circuits.

DNA logic nanodevices are powerful tools for both molecular computing tasks and smart bioanalytical applications. Nevertheless, the hour-level operation time and high cost caused by the frequent redesign/reconstruction of gates, tedious strand-displacement reaction, and expensive labeled probes (or tool enzymes) in previous works are ineluctable drawbacks. Herein, we report an ultrafast and cost-effective system for engineering concurrent DNA logic nanodevices (CDLNs) by combining polythymine CuNCs with SYBR Green I (SG I) as universal dual-output producers.

The one/two atom size-reduction of [AuSCy] induced by the [Au(dppp)] cluster.

The recent progress in atomically precise metal (Au, Ag ) nanoclusters has greatly enriched the molecular-level mechanistic understanding of metal nanomaterials. Herein, using two meta-stable (easy formation, easy transformation) clusters, [AuSCy] and [Au(dppp)] (HSCy and dppp denote cyclohexanethiol and 1,3-bis(diphenylphosphino)propane), as the reaction precursors, the etching of Au occurs smoothly, giving the one/two-atom size-reduced [AuSCy(dppp)] and [AuSCy(dppp)] as the major products. Structural analysis and DFT calculations indicate that the active reaction site of Au lies in the core-shell interference of the bi-capped icosahedral Au core and the AuS motifs.

Integration of G-Quadruplex and Pyrene as a Simple and Efficient Ratiometric Fluorescent Platform That Programmed by Contrary Logic Pair for Highly Sensitive and Selective Coralyne (COR) Detection.

The effective and accurate detection of the anticancer drug coralyne (COR) is highly significant for drug quality control, medication safety and good health. Although various COR sensors have been reported in recent years, previous ones can only exhibit single-signal output (turn ON or turn OFF) with poor reliability and anti-interference ability. Therefore, exploring novel platform with dual-signal response for COR detection is urgently needed.

An Oligopeptide-Protected Ultrasmall Gold Nanocluster with Peroxidase-Mimicking and Cellular-Imaging Capacities.

Recent decades have witnessed the rapid progress of nanozymes and their high promising applications in catalysis and bioclinics. However, the comprehensive synthetic procedures and harsh synthetic conditions represent significant challenges for nanozymes. In this study, monodisperse, ultrasmall gold clusters with peroxidase-like activity were prepared via a simple and robust one-pot method.

Recent advancements in coralyne (COR)-based biosensors: Basic principles, various strategies and future perspectives.

As a kind of protoberberine alkaloid heterocyclic analogues, coralyne (COR) has been reported to exhibit superior antileukemic ability and used as anticancer drug agent. While, the severe hazards and side effects caused by unreasonable use have made its accurate detection more and more important. Although scientists have explored various methods to sense COR and other related targets, a systematical review which could not only elaborate recent developments and analyze current challenges of COR-based biosensors, but also present future perspective has not been reported and is urgently needed.

Evaluation of Macular and Retinal Ganglion Cell Count Estimates for Detecting and Staging Glaucoma.

To investigate the clinical significance of macular estimated retinal ganglion cell (mRGC) and estimated retinal ganglion cell (eRGC) in the diagnosis and staging of glaucoma. This is a cross-section study. All enrolled subjects underwent standard automated perimetry (SAP) and optical coherence tomography (OCT) examination.

Triggered Dimerization and Trimerization of DNA Tetrahedra for Multiplexed miRNA Detection and Imaging of Cancer Cells.

The reversible and switchable triggered reconfiguration of tetrahedra nanostructures from monomer tetrahedra structures into dimer or trimer structures is introduced. The triggered bridging of monomer tetrahedra by K -ion-stabilized G-quadruplexes or T-A•T triplexes leads to dimer or trimer tetrahedra structures that are separated by crown ether or basic pH conditions, respectively. The signal-triggered dimerization/trimerization of DNA tetrahedra structures is used to develop multiplexed miRNA-sensing platforms, and the tetrahedra mixture is used for intracellular sensing and imaging of miRNAs.

Propelling DNA Computing with Materials' Power: Recent Advancements in Innovative DNA Logic Computing Systems and Smart Bio-Applications.

DNA computing is recognized as one of the most outstanding candidates of next-generation molecular computers that perform Boolean logic using DNAs as basic elements. Benefiting from DNAs' inherent merits of low-cost, easy-synthesis, excellent biocompatibility, and high programmability, DNA computing has evoked substantial interests and gained burgeoning advancements in recent decades, and also exhibited amazing magic in smart bio-applications. In this review, recent achievements of DNA logic computing systems using multifarious materials as building blocks are summarized.

Modeling Gene Expression Instability by Programmed and Switchable Polymerization/Nicking DNA Nanomachineries.

Models for gene expression instability by noncanonical DNA-nanostructures are introduced. The systems consist of a promoter-template scaffold that acts as a polymerization/nicking machinery that models, in the presence of polymerase/Nt.BbvCI and dNTPs, the autonomous synthesis of displaced strands mimicking the native "genes".

Illuminating Diverse Concomitant DNA Logic Gates and Concatenated Circuits with Hairpin DNA-Templated Silver Nanoclusters as Universal Dual-Output Generators.

Exquisite administration of a new type of hairpin DNA-templated silver nanoclusters (H-AgNCs) as universal dual-output generators in DNA-based logic systems is reported. Diverse concomitant contrary logic gates (CCLGs) with opposite functions (YES NOT, OR NOR, INHIBIT IMPLICATION, XOR XNOR, and MAJORITY MINORITY) and extended concatenated logic circuits are presented and some of them perform specific functions, such as parity generators and checkers. The introduction of H-AgNCs as noncovalent signal reporters avoids tedious and high-cost labeling procedures.

A Janus-inspired amphichromatic system that kills two birds with one stone for operating a "DNA Janus Logic Pair" (DJLP) library.

Although DNA computing has exhibited a magical power across diverse areas, current DNA logic gates with different functions are always separately operated and can only produce hard-to-visualize output. The fussy/obligatory gates' redesign/reconstruction and the non-intuitive output cause the wastage of time and costs, low efficiency and practicality. Herein, inspired by the ancient Roman mythical God Janus, for the first time, we propose the concept of "DNA Janus Logic Pair" (DJLP) to classify the DNA logic gates with contrary functions into "Positive + Negative" gates (DJLP = Pos + Neg).

A simple, label-free, electrochemical DNA parity generator/checker for error detection during data transmission based on "aptamer-nanoclaw"-modulated protein steric hindrance.

Versatile DNA logic devices have exhibited magical power in molecular-level computing and data processing. During any type of data transmission, the appearance of erroneous bits (which have severe impacts on normal computing) is unavoidable. Luckily, the erroneous bits can be detected placing a parity generator (pG) at the sending module and a parity checker (pC) at the receiving module.

Chemiluminescence of CsPbBr Perovskite Nanocrystal on the Hexane/Water Interface.

All-inorganic halide perovskite CsPbBr nanocrystals (NCs) have attracted more attention in recent years due to the unique optical feature. To date, most of the research was mainly focused on the photoluminescence (PL) and electrochemiluminescence (ECL) of the perovskite NCs. In this work, the strong chemiluminescence (CL) emission of CsPbBr NCs was observed for the first time on the hexane/water interface with the assistance of ammonium persulfate-(NH)SO as coreactant.

Introducing Ratiometric Fluorescence to MnO Nanosheet-Based Biosensing: A Simple, Label-Free Ratiometric Fluorescent Sensor Programmed by Cascade Logic Circuit for Ultrasensitive GSH Detection.

Glutathione (GSH) plays crucial roles in various biological functions, the level alterations of which have been linked to varieties of diseases. Herein, we for the first time expanded the application of oxidase-like property of MnO nanosheet (MnO NS) to fluorescent substrates of peroxidase. Different from previously reported fluorescent quenching phenomena, we found that MnO NS could not only largely quench the fluorescence of highly fluorescent Scopoletin (SC) but also surprisingly enhance that of nonfluorescent Amplex Red (AR) via oxidation reaction.

A DNA-based parity generator/checker for error detection through data transmission with visual readout and an output-correction function.

During any type of binary data transmission, the occurrence of bit errors is an inevitable and frequent problem suffered. These errors, which have fatal effects on the correct logic computation, especially in sophisticated logic circuits, can be checked through insertion of a parity generator (pG) at the transmitting end and a parity checker (pC) at the receiving end. Herein, taking even pG/pC as a model device, we constructed the first DNA-based molecular parity generator/checker (pG/pC) for error detection through data transmission, on a universal single-strand platform according to solely DNA hybridization.

Tyramine Hydrochloride Based Label-Free System for Operating Various DNA Logic Gates and a DNA Caliper for Base Number Measurements.

DNA is believed to be a promising candidate for molecular logic computation, and the fluorogenic/colorimetric substrates of G-quadruplex DNAzyme (G4zyme) are broadly used as label-free output reporters of DNA logic circuits. Herein, for the first time, tyramine-HCl (a fluorogenic substrate of G4zyme) is applied to DNA logic computation and a series of label-free DNA-input logic gates, including elementary AND, OR, and INHIBIT logic gates, as well as a two to one encoder, are constructed. Furthermore, a DNA caliper that can measure the base number of target DNA as low as three bases is also fabricated.

Exploiting Polydopamine Nanospheres to DNA Computing: A Simple, Enzyme-Free and G-Quadruplex-Free DNA Parity Generator/Checker for Error Detection during Data Transmission.

Molecular logic devices with various functions play an indispensable role in molecular data transmission/processing. However, during any kinds of data transmission, a constant and unavoidable circumstance is the appearance of bit errors, which have serious effects on the regular logic computation. Fortunately, these errors can be detected via plugging a parity generator (pG) at the transmitting terminal and a parity checker (pC) at the receiving terminal.

Polydopamine Nanotubes as an Effective Fluorescent Quencher for Highly Sensitive and Selective Detection of Biomolecules Assisted with Exonuclease III Amplification.

In this work, the effective fluorescence quenching ability of polydopamine nanotubes (PDANTs) toward various fluorescent dyes was studied and further applied to fluorescent biosensing for the first time. The PDANTs could quench the fluorophores with different emission frequencies, aminomethylcoumarin acetate (AMCA), 6-carboxyfluorescein (FAM), 6-carboxytetramethylrhodamine (TAMRA), and Cy5. All the quenching efficiencies reached to more than 97%.

Cascaded multiple amplification strategy for ultrasensitive detection of HIV/HCV virus DNA.

Ultrasensitive detection of HIV and HCV virus DNA is of great importance for early accurate diagnostics and therapy of HIV virus-infected patients. Herein, to our best knowledge, it is the first to use DNA cascaded multiple amplification strategy for ultrasensitive detection of HIV virus DNA with G-quadruplex-specific fluorescent or colorimetric probes as signal carriers. The developed strategy also exhibited universal applicability for HCV virus DNA detection.

A label-free colorimetric aptasensor for simple, sensitive and selective detection of Pt (II) based on platinum (II)-oligonucleotide coordination induced gold nanoparticles aggregation.

Herein, a gold nanoparticles (AuNPs) based label-free colorimetric aptasensor for simple, sensitive and selective detection of Pt (II) was constructed for the first time. Four bases (G-G mismatch) mismatched streptavidin aptamer (MSAA) was used to protect AuNPs from salt-induced aggregation and recognize Pt (II) specifically. Only in the presence of Pt (II), coordination occurs between G-G bases and Pt (II), leading to the activation of streptavidin aptamer.

Cascade DNA logic device programmed ratiometric DNA analysis and logic devices based on a fluorescent dual-signal probe of a G-quadruplex DNAzyme.

Herein, two fluorescence sensitive substrates of G-quadruplex/hemin DNAzyme with inverse responses (Scopoletin and Amplex Red) were simultaneously used in one homogeneous system to construct a cascade advanced DNA logic device for the first time (a functional logic device (a three input based DNA calliper) cascade with an advanced non-arithmetic logic gate (1 to 2 decoder)). This cascade logic device was applied to label-free ratiometric target DNA detection and length measurement.

Colorimetric Strategy for Highly Sensitive and Selective Simultaneous Detection of Histidine and Cysteine Based on G-Quadruplex-Cu(II) Metalloenzyme.

In this present work, we proposed a colorimetric strategy for simultaneous detection of histidine and cysteine based on G-quadruplex-Cu(II) metalloenzyme for the first time. Because of the adding of histidine or cysteine, the formation of G-quadruplex-Cu(II) metalloenzyme will be disturbed, thus the catalytic activity to TMB-H2O2 reaction is inversely proportional to the concentration of histidine or cysteine. With this strategy, the limit of detection in experimental measurement for histidine and cysteine is 10 nM and 5 nM, respectively, which are both lower than previous colorimetric arrays.