Field Of Biological Analysis Research Articles

Upconversion nanoparticles-CuMnO2 nanoassemblies for NIR-excited imaging of reactive oxygen species in vivo

Here, we designed a ratiometric luminescent nanoprobe based on lanthanide-doped upconversion nanoparticles-CuMnO2 nanoassemblies for rapid and sensitive detection of reactive oxygen species (ROS) levels in living cells and mouse. CuMnO2 nanosheets exhibit a wide absorption range of 300–700 nm, overlapping with the visible-light emission of upconversion nanoparticles (UCNPs), resulting in a significant upconversion luminescence quenching. In an acidic environment, H2O2 can promote the redox reaction of CuMnO2, leading to its dissociation from the surface of UCNPs and the restoration of upconversion luminescence. The variation in luminescence intensity ratio (UCL475/UCL450) were monitored to detect ROS levels. The H2O2 nanoprobe exhibited a linear response in the range of 0.314–10 μM with a detection limit of 11.3 nM. The biological tests proved the excellent biocompatibility and low toxicity of obtained UCNPs-CuMnO2 nanoassemblies. This ratiometric luminescent nanoprobe was successfully applied for the detection of exogenous and endogenous ROS in live cells as well as in vivo ROS quantitation. The dual transition metal ions endow this probe efficient catalytic decomposition capabilities, and this sensing strategy broadens the application of UCNPs-based nanomaterials in the field of biological analysis and diagnosis.

Impact electrochemistry for biosensing: advances and future directions.

Impact electrochemistry allows for the investigation of the properties of single entities, ranging from nanoparticles (NPs) to soft bio-particles. It has introduced a novel dimension in the field of biological analysis, enhancing researchers' ability to comprehend biological heterogeneity and offering a new avenue for developing novel diagnostic devices for quantifying biological analytes. This review aims to summarize the recent advancements in impact electrochemistry-based biosensing over the past two to three years and provide insights into the future directions of this field.

Nanosensor Based on the Dual-Entropy-Driven Modulation Strategy for Intracellular Detection of MicroRNA.

The entropy-driven strategy has been proposed as a milestone work in the development of nucleic acid amplification technology. With the characteristics of an enzyme-free, isothermal, and relatively simple design, it has been widely used in the field of biological analysis. However, it is still a challenge to apply entropy-driven amplification for intracellular target analysis. In this study, a dual-entropy-driven amplification system constructed on the surface of gold nanoparticles (AuNPs) is developed to achieve fluorescence determination and intracellular imaging of microRNA-21 (miRNA-21). The dual-entropy-driven amplification strategy internalizes the fuel chain to avoid the complexity of the extra addition in the traditional entropy-driven amplification strategy. The unique self-locked fuel chain system is established by attaching the three-stranded structure on two groups of AuNPs, where the Cy5 fluorescent label was first quenched by AuNPs. After the target miRNA-21 is identified, the fuel chain will be automatically unlocked, and the cycle reaction will be driven, leading to fluorescence recovery. The self-powered and waste-recycled fuel chain greatly improves the automation and intelligence of the reaction process. Under the optimal conditions, the linear response range of the nanosensor ranges from 5 pM to 25 nM. This nanoreaction system can be used to realize intracellular imaging of miRNA-21, and its good specificity enables it to distinguish tumor cells from healthy cells. The development of the dual-entropy-driven strategy provides an integrated and powerful way for intracellular miRNA analysis and shows great potential in the biomedical field.

Imide-functionalized Cu-MOF: Biomimetic peroxidase activity and detection of hydrogen peroxide and ascorbic acid

The synthesis of MOF with imide-functionalized aromatic conjugated carboxylic acid ligands has been a hot topic of field. A novel biomimetic peroxidase material (Cu-BDCPPI) was designed, synthesized and characterized by combining imide-functionalized aromatic conjugated carboxylic acid ligands N, N′-bis (3,5-dicarboxyphenyl) homophthalic diimide (H4BDCPPI) and catalytically active copper ions. The potential catalytic effect of Cu-H4BDCPPI on peroxidase-like activity was found firstly. It can catalyze the typical colorimetric substrate 3,3′,5,5′-tetramethylbenzyl (TMB) from colorless to blue ox-TMB in the presence of H2O2, and its enzymatic catalytic activity is similar to that of natural horseradish peroxidase (HRP). So, based on the catalytic performance of Cu-BDCPPI, a colorimetric method and test strips can be established for the detection of H2O2 and ascorbic acid (AA). This work provides a feasible strategy for synthesizing MOF materials with peroxidase like properties, expanding the application of MOF materials in the field of biological analysis.

Research progress in rolling circle amplification in biosensing and cell imaging

<p indent="0mm">Rolling circle amplification (RCA) is an isothermal nucleic acid amplification technology that performs massive amplification of rolling circle replication by hybridizing with target nucleic acid DNA, which has the advantages of simplicity, rapidity and high amplification efficiency. RCA technology has been widely used in the field of biological analysis, especially in the field of sensor detection and cell imaging analysis of nucleic acid, protein, exosome, virus and other disease biomarkers. In this paper, the basic principles and classification of RCA technology are introduced, the research progress of RCA technology in the field of biosensing and cell imaging in recent years is systematically reviewed, and the shortcomings and improvement strategies of RCA technology are proposed.

A new peptide-mediated COF nanocatalytic amplification SERS quantitative assay for ultratrace Cu2+

Peptides are an important recognition element for small molecules and have been used in the field of biological analysis. However, it has been rarely reported that a novel method combining peptides as recognition elements with covalent organic framework (COF) as catalytic amplification signal to construct highly sensitive and selective three-mode molecular spectroscopy. In this paper, high catalytic and stable three COFs were prepared, and the catalysis of the new indicator nanoreaction of HAuCl4-sodiumformate (Fo) was studied by molecular spectral slope procedure. The produced gold nanoparticles (AuNPs) exhibit a strong resonance Rayleigh scattering (RRS) peak at 370 nm and surface plasmon resonance absorption (Abs) peak at 540 nm. In the presence of molecular probes, a strongest surface-enhanced Raman scattering (SERS) peak was generated at 1617 cm−1. Combining the COFTpBD amplification indicator reaction with specific peptide (PT) reaction of Cu2+, a novel, sensitive and selective SERS/RRS/Abs assay platform was established, with a SERS linear range of 0.005–0.115 nmol/L Cu2+. In addition, the two working curves of lg[Cu2+] vs SERS and [Cu2+] vs SERS intensity, and the nanocatalytic mechanism were discussed.

A cross-mixing channel 3D-SAR micromixer with high mixing performance

Abstract As an important part of laboratory-on-a-chip (LOC) and micro-total analysis system (μTAS), micromixers are widely used in the fields of biological analysis and chemical synthesis. Most of them are used for the pretreatment of the detection and analysis system to realize the full mixing between the sample and the target to improve the accuracy of the inspection system. A new type of 3D-SAR micromixer with cross-channel structures was put forward after the systemic simulation by using CFD software. The mixing performance and mechanism of 3D-SAR micromixer with/without cross-mixing channel has been investigated with different Reynolds numbers (Re). The results show that the 3D-SAR micromixer with or without cross-mixing channel structures are of excellent mixing performance when the Re was high (Re &gt; 50), and the mixing index is close to 1. While the concentration stratification of the two fluids in the cross-mixing channel (CMC) 3D-SAR micromixer is obviously better than that of no-cross-mixing channel (NCMC) 3D-SAR micromixer when Re is low (Re &lt; 10). It is because the two fluids in the cross-mixing channel rotate counterclockwise at the mixing unit, which induces a vortex and increases the contact area between the two fluids. The mixing performance is greatly improved, and the mixing index at the outlet is more than 0.9. Meanwhile, in order to optimize the higher pressure drop of the CMC micromixer, a new 3D-SAR micromixer with the unbalanced-cross-mixing channel (UCMC) is proposed based on the CMC structure. This channel structure can meet the requirements of high mixing index and low-pressure drop at the same time, which is helpful to design and manufacture of new type micromixer.

Applications of DNA bases, Graphene and Biosensors : A Critical Review

The current research paper presents a theoretical exploration of the interaction between 2-D nanomaterials and the DNA bases that embody graphene properties and biosensors applications. Regarding its role as a conveyer of genetic information, Deoxyribonucleic acid (DNA) has been understood as a constructed substance for various components and structural collations with nanoparticle merits. It is counted as the bearer of genetic information in the human being's life, where it is a fundamental biomacromolecule in almost all living apparatuses. Because of DNA's self-recognition characteristics (based on the specific base pairing of G-C and T-A), more attention has been drawn to monolayer films of nucleic acids. It is seen that many doping techniques have been carefully investigated. Thus, this survey article provides a new and comprehensive outline of the modern strategies that include specifically immobilized DNA on Graphene. further, it is expected in the near future that there will be a designee of DNA nanodevices that are distinguished in smartness, accuracy, and sensitivity where they will contribute to the fields of biological analysis, clinical diagnosis, and biomedicine

High-performance cascade nanoreactor based on halloysite nanotubes-integrated enzyme-nanozyme microsystem

Various enzymatic reactions or enzymatic cascade reactions occur efficiently in biological microsystems due to space constraints or orderly transfer of intermediate products. Inspired by this, the horseradish peroxidase (HRP)-like nanozyme (Fe-aminoclay) was in situ synthesized on the surface of alkali-activated halloysite nanotubes and the natural enzyme (glucose oxidase, GOx) was immobilized on it to construct a high-efficiency GOx-FeAC@AHNTs cascade nanoreactor. In which, FeAC@AHNTs can not only be used as a carrier for immobilized enzymes, but also help its catalytic activity to cooperate with glucose oxidase in a cascade reaction. The microcompartments and substrate channel effect of this enzyme-nanozyme microsystem exhibit a superior catalytic performance than that of natural enzyme system, and exhibits excellent long-term stability and recyclability. Subsequently, the GOx-FeAC@AHNTs cascade nanoreactor was employed as a glucose colorimetric platform, which displayed a low detection limit (0.47 µmol/L) in glucose detection. This enzyme-nanoenzyme nanoreactor provides a simple and effective example for constructing a multi-enzyme system with limited space, and lays the foundation for subsequent research in the fields of biological analysis and catalysis.

Multifunctional DNA mediated spatially confined assembly for antibody orientation: Surpassing sensitivity and accuracy for rituximab detection

The sensitive, accurate and fast monitoring of therapeutic drugs plays an important role in guiding clinical medication or individualized treatment. Inspired by the highly efficient interactions of ordered structures in living organisms, a multifunctional DNA mediated spatially confined assembly (SCA) based antibody orientation strategy was proposed in this work. The multifunctional DNA containing a signaling molecule labeled on the head and a poly adenine tail (20 bases), can not only direct the ordered immobilization of antibodies on gold nanoparticles, but can also enrich electrochemical signal molecules. Compared with a randomly arranged antibody immobilization strategy, the SCA based antibody orientation strategy can produce nearly 200% of peak current signal. Moreover, MoS2/gold nanoparticles were used to modify electrodes in this study in order to improve the electrochemically active surface area and electron transfer of the electrode as well as the spatial regulation of thiol peptides. By using a highly specific CD20 epitope mimetic peptide this proposed biosensor exhibits high sensitivity for rituximab detection (LOD 56.4 fM) as well as good selectivity, stability and satisfactory accuracy. When applying it for detecting rituximab in lymphoma patients’ plasma, comparable results to commercial ELISA were obtained with a low RSD (＜6.5%). The proposed signal tag fabrication strategy could easily be extended to analyze other targets by changing the sensing platform, which has a potential application in the fields of biological analysis and medical diagnosis.

Study on the Biosensor Based on Biomimetic PDA Vesicles Fluorescence Resonance Energy Transfer for the Determination of Ovarian Cancer Marker miRNA-21.

In recent years, more and more research is being conducted on microRNAs and their involvement in the regulation of autophagy phagocytosis which is closely related to tumor growth. MicroRNA-21 is a kind of small RNA that can regulate gene expression and plays a significant role in autophagy of tumor cells. But the detection of microRNAs had always been a problem in the field of biological analysis. In this study, we designed a new fluorescent sensor for the detection of miRNA-21. The sensor was based on the successful signal reporting by E36-encapsulated vesicles and the specific interaction between E36 and miRNA-21. In the presence of miRNA, the E36/miRNA-21 complex formed and served as a donor molecule inside the acceptor PDA vesicles to amplify the fluorescence through FRET. Additionally, the sensor was applied to detect miRNA-21 in complex biological samples with satisfactory results.

A one-step method to fabricate bio-friendly patterned superhydrophobic surface by atmospheric pressure cold plasma

Superhydrophobic surfaces have special restrictions and manipulation capabilities on liquids, and have great potential applications in fields of biological analysis. However, the preparation of bio-friendly superhydrophobic surfaces by high efficiency methods remains a challenge. In this work, a new one-step preparation method to fabricate bio-friendly superhydrophobic surface based on atmospheric pressure cold plasma is proposed. Using argon as the working gas and HMDSN as the monomer, the superhydrophobic surface can be prepared in one step by APCP whether on the surface of conductive metal, the surface of a flexible paper, or the surface of hard and brittle glass. The plasma characteristics, surface wettability, surface morphology, chemical composition, adhesion performance and bounce phenomenon have been systematically studied, which proves the excellent performance of the prepared superhydrophobic surface. Finally, the bio-friendly properties were verified by the cultivation of Hela cell, Escherichia coli, the seeds of bacopa monnieri and clover on the prepared superhydrophobic surface. This work shows great potential in applications for biological system cultivation and analysis.

Peptide Cleavage-Mediated and Environmentally Friendly Photocurrent Polarity Switching System for Prostate-Specific Antigen Assay.

As the most important serum biomarker for prostate cancer, sensitive and accurate detection of prostate-specific antigen (PSA) is of great reference value for the clinical diagnosis and treatment of prostate cancer. Herein, a peptide cleavage-mediated and environmentally friendly photocurrent polarity switching system was developed for ultrasensitive and highly selective detection of PSA based on the efficiently switching of photocurrent polarity of silver indium sulfide nanoparticles (AgInS2 NPs)-coated indium tin oxide (ITO) electrode by amino-functionalized CuO cubes (NH2-CuO). The porous CuO cubes were synthesized by calcination of HKUST-1 and functionalized with aminosilane. In the presence of PSA, the biotin and rhodamine B-labeled peptide (Bio-Pep-RhB) was cleaved and part of the peptide (P-Pep-RhB) was obtained by magnetic separation. Through host-guest recognition between β-CD and RhB, the P-Pep-RhB was immobilized on the β-CD/AgInS2 NPs/ITO electrode. Then, the amino-rich sequence on P-Pep-RhB combined with NH2-CuO via glutaraldehyde results in the switch of anodic photocurrent to cathodic photocurrent. On account of the high-efficient peptide cleaving strategy and the new photocurrent polarity switching system of porous CuO cubes//AgInS2 NPs, the prepared sensing platform displayed outstanding analytical performance for PSA with a wide linear response range (0.1 pg mL-1-100 ng mL-1) and a lower detection limit of 0.06 pg mL-1. The proposed analytical method could be easily extended to analyze other proteins via changing the peptide sequence, which has a potential application in the fields of biological analysis and medical diagnosis.

One‐step synthesis of cationic gold nanoclusters with high catalytic activity on luminol chemiluminescence reaction

AbstractThe present study reports a one‐step synthesis method for the preparation of cationic gold nanoclusters (Au NCs). Polyethyleneimine (PEI), a positively charged hyperbranched polyamine, was selected as the capping reagent. Glutathione showed a synergistic effect on the formation of the small size of cationic Au NCs. The prepared cationic Au NCs have a size less than 2 nm and carry a positive charge in solution with pH less than 11. The cationic PEI–Au NCs‐triggered luminol chemiluminescence (CL) reactions showed slow and intense CL profiles. The maximum CL intensity can be obtained within 10 min and the CL signal maintained almost the same within 30 min. A linear increase of CL intensity was observed in the presence of an increasing concentration of cationic Au NCs ranging from 0.030 μM to 15 μM. The linear response of the cationic Au NCs in the CL reaction and the glow‐type CL profile make the proposed CL reaction have broad application prospects in the field of biological analysis and CL imaging.

Fabrication of graphene oxide and sliver nanoparticle hybrids for fluorescence quenching of DNA labeled by methylene blue.

Since graphene oxide‑silver nanoparticles (GO-AgNPs) have special affinities to DNA, it become increasingly important in fields of biological analysis in which GO-AgNPs nanocomposites universally functioned as a quencher. In this paper, GO-AgNPs nanocomposites with different GO to AgNPs ratios were synthesized as a fluorescence quencher to interact with DNA labeled by methylene blue (MB). The results showed that the fluorescence intensity of DNA-MB system decreased with the increasing of GO-AgNPs nanocomposites concentration. The quenching phenomenon of DNA-MB by AgNPs and GO was not a simple additive effect but a synergistic effect. The quenching efficiency of synthesized GO-AgNPs nanocomposites with different ratios (1:1, 1:3, 1:5, 1:10) increased with the decrease of GO/Ag ratio. Thermodynamic analysis was employed to investigate the interaction of GO-AgNPs and DNA-MB, it can be concluded that the intermolecular force between GO-AgNPs and DNA-MB was hydrogen bonding. Our works will provide important theoretical and experimental bases for fluorescence sensing of DNA.

Ultrasensitive Poly(boric acid) Hydrogel-Coated Quartz Crystal Microbalance Sensor by Using UV Pressing-Assisted Polymerization for Saliva Glucose Monitoring.

Quartz crystal microbalance (QCM) has attracted extensive attention in the field of biological analysis and detection because of its high sensitivity, fast response, real-time measurement, good operability, and low-cost production. However, to detect the trace amounts of small molecules, such as low-concentration saliva glucose under physiological conditions, is still a major challenge. Herein, the surface of a QCM chip was coated with a poly(boric acid)-based hydrogel using UV pressing-assisted polymerization to obtain a simple device for glucose detection. The designed QCM sensor shows a record-low detection limit of glucose (3 mg/L at pH 7.5), which is ∼30 times lower than that of sensors fabricated by conventional surface initiation-spin coating. The outperformance of the poly(boric acid) hydrogel-coated QCM sensor is probably due to the uniform and compact microstructure, as well as the presence of sufficient glucose-binding sites resulting from the hydrogel coating generated by UV pressing-assisted polymerization. This method provides an important solution to detect the trace amounts of small organic molecules or ions and has the potential to push forward the practical applications of QCM sensors.

Orientation Control of the Molecular Recognition Layer for Improved Sensitivity: a Review

Biosensors have been used in various fields of biological analysis, such as for quantification of analytes and the study of molecule-molecule interactions. Orientation control of the molecular recognition layer is one of the easiest and most effective ways to improve the sensitivity of biosensors. In this review, the orientation control of molecular recognition molecules, such as antibodies, aptamers, and enzymes, is discussed. The review compares the improvement in the sensitivity and binding activity of biosensors achieved through orientation control with that achieved through random orientation. Immobilization methods of antibodies for orientation control are first discussed, with a focus on immobilization of the fragment crystallizable region of antibodies, which is the most studied technique. Covalent and non-covalent immobilization strategies are also discussed, and their effect on the sensitivity of biosensors is summarized. Lastly, the orientation control of other molecular recognition molecules (aptamers and enzymes) was discussed and the applications of molecular recognition molecules as biosensors are discussed.

A Novel Direct PCR Lysis Buffer Can Improve PCR from Meat Matrices

Molecular technologies based on PCR have been widely used in many biological analysis fields, especially for genetic analysis and DNA barcoding. In this study, a rapid DNA lysis liquid was formulated without any purification step from fresh and processed meat, suitable for conventional PCR amplification. Three different lysis liquid formulas were designed for selection and further optimization for direct PCR and absorbance spectra; DNA concentration and performance in PCR were used to assess the effect of each formula. The results indicated that the formula containing NaOH, EDTA, SDS, Tween 20, and Tris-HCl achieved the best results, and the optimized formula met the need of practical PCR applications. The protocol provided a rapid lysis buffer for DNA replication from any meat samples. The performance of the final formula resulted in high DNA lysis efficiencies for all the tested meat samples and the PCR amplification efficiencies were similar to isolated DNA template using a commercial kit. The whole process can be completed in 30 min. Therefore, this study provides a simple, alternative, cost-effective fast solution for meat molecular analysis based on DNA.

Exploring the ability of the nalidixate to sensitize visible and near-infrared emitting lanthanide(III) cations

Recently, a strong interest has been directed towards near-infrared (NIR) emitting lanthanide(III) compounds as they do possess complementary advantages in respect to organic molecules and semi-conductor nanocrystals, especially in the fields of biological analysis and imaging. To benefit from their emission, a key requirement to fulfill is the sensitization of lanthanide(III) cations with an appropriate chromophore. This condition is especially challenging to address for the lanthanide(III) cations emitting in the NIR. The quest for new chromophores well adapted to the NIR-emitting lanthanide(III) ions is an important direction of research in order to broaden the rationalization of the parameters that control the sensitization process. In this work, we have investigated the ability of a readily available chromophoric ligand, the nalidixic acid, to sensitize lanthanide(III) cations with a specific interest for those emitting in the NIR. We have therefore performed an extensive study of the luminescence properties of lanthanide(III) complexes emitting in the visible and in the NIR ranges formed in situ upon mixing the corresponding Ln(III) nitrates (Ln(III) = Pr, Nd, Sm, Eu, Tb, Dy, Ho, Tm, Yb) with nalidixic acid (HNA) in a 1:3 molar ratio in the presence of a base. Luminescence spectra, quantum yields and luminescence lifetimes have been measured and discussed. The red emission of Eu with a quantum yield value of 5.90(3)%, red and NIR of Pr (7(1) · 10−4 and 5.6(1) · 10−4%) and Ho (9.3(2) · 10−4 and 2.8(1) · 10−4%), green of Tb (5.21(5)%), yellow and NIR of Dy (0.51(2) and 0.065(4)%), orange and NIR of Sm (0.147(5) and 0.037(2)%), as well as NIR of Nd (0.0321(2)%) and Yb (0.021(1)%) were observed. These results and analysis show that the nalidixate is a versatile chromophoric ligand that is suitable for the sensitization of nine different lanthanide(III) cations, five of them emitting in the NIR.

A novel amperometric adenosine triphosphate biosensor by immobilizing graphene/dual-labeled aptamers complex onto poly(o-phenylenediamine) modified electrode

Graphene (GR) can strongly interact with aptamers due to hydrophobic and π–π stacking interactions between nucleotide bases and GR, but hardly interact with aptamer–target complexes or rigid double-stranded DNA. The unique GR/aptamers interaction has been fascinatingly developed in fluorescent assay, colorimetric biosensing and mass spectrometric analysis. However, exploration of the unique GR/aptamers interaction in electrochemical biosensing is still at an early stage. In this regard, we reported herein a novel, sensitive and relatively cushy approach to construct electrochemical aptasensors by immobilizing GR/aptamers complex on the surface of poly(o-phenylenediamine) (PoPD) modified glassy carbon electrodes (GCE). Adenosine triphosphate (ATP) was chosen as a model analyte and a well-studied 27-mer single-stranded DNA aptamer was tailor-made to have methylene-blue (Mb) at both ends for use as an electrochemical probe. The Mb-dual-labeled aptamers/GR/PoPD/GCE exhibited a strong electrochemical signal due to the high electrons transfer and large surface area of GR and using double Mb labeled at two ends of aptamers. The presence of ATP triggers the structure switching of aptamer to form aptamer–ATP complex, causing the destruction of the interaction between aptamer and GR and thus the release of Mb-dual-labeled aptamer from the GR, resulting in a low electrochemical signal. Under optimal conditions, we have successfully detected ATP down to a detection limit of 0.3nM with a wide detection range of 10nM–2mM. And from the experiment of cancer cellular ATP assay, it is proved that the method may have great prospects in the field of biological analysis.