Ultra-rapid and highly efficient enrichment of organic pollutants via magnetic nanoparticles/mesoporous nanosponge compounds for ultrasensitive nanosensors

Abstract Developing advanced sensing and detection technologies to effectively monitor organic micropollutants in water is under urgent demand in both scientific and industrial communities. Currently, owing to the ultrahigh sensitivity on the single-molecule level with highly informative spectra characteristics, SERS technique is regarded as the most direct and effective detection technique. However, some weakly adsorbed molecules, such as most of persistent organic pollutants, cannot exhibit strong SERS signals, which is a long-standing key challenge that has not been solved. Here, we show an enrichment-typed sensing strategy based on a powerful porous composite material, call mesoporous nanosponge. The nanosponge consists of magnetic nanoparticles immobilized porous β-cyclodextrin polymers, demonstrating remarkable capability of effective and fast removal of organic micropollutants, e.g. ~90% removal efficiency within ~1 min. With the anchoring of magnetic nanoparticles, the current new polymer adsorbent can be easily recycled from water and re-dispersed in ethanol so that the target molecules in the cavity of adsorbent is concentrated, with an enrichment factor up to ~103. By means of the current enrichment strategy, the limit of detection (LOD) of the typical organic pollutants can be significantly improved, i.e. increasing 2~3 orders of magnitude, compared with the detection without molecule enrichment protocol. Consequently, the current enrichment strategy is proved to be applicable in a variety of fields for portable and fast detection, such as Raman and fluorescent.

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Ultra-rapid and highly efficient enrichment of organic pollutants via magnetic mesoporous nanosponge for ultrasensitive nanosensors

Nature Communications ◽

10.1038/s41467-021-27100-2 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Lingling Zhang ◽

Yu Guo ◽

Rui Hao ◽

Yafei Shi ◽

Hongjun You ◽

...

Keyword(s):

Organic Pollutants ◽

Single Molecule ◽

Cross Sections ◽

Limit Of Detection ◽

Detection Sensitivity ◽

Practical Applications ◽

Single Molecule Level ◽

Surface Enhanced Raman ◽

Low Sensitivity ◽

Enrichment Strategy

AbstractCurrently, owing to the single-molecule-level sensitivity and highly informative spectroscopic characteristics, surface-enhanced Raman scattering (SERS) is regarded as the most direct and effective detection technique. However, SERS still faces several challenges in its practical applications, such as the complex matrix interferences, and low sensitivity to the molecules of intrinsic small cross-sections or weak affinity to the surface of metals. Here, we show an enrichment-typed sensing strategy with both excellent selectivity and ultrahigh detection sensitivity based on a powerful porous composite material, called mesoporous nanosponge. The nanosponge consists of porous β-cyclodextrin polymers immobilized with magnetic NPs, demonstrating remarkable capability of effective and fast removal of organic micropollutants, e.g., ~90% removal efficiency within ~1 min, and an enrichment factor up to ~103. By means of this current enrichment strategy, the limit of detection for typical organic pollutants can be significantly improved by 2~3 orders of magnitude. Consequently, the current enrichment strategy is proved to be applicable in a variety of fields for portable and fast detection, such as Raman and fluorescent sensing.

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Magnetic Nanoparticles as a Tool for Remote DNA Manipulations at a Single-Molecule Level

ACS Applied Materials & Interfaces ◽

10.1021/acsami.0c21002 ◽

2021 ◽

Vol 13 (12) ◽

pp. 14458-14469

Author(s):

Aleksey A. Nikitin ◽

Anton Yu Yurenya ◽

Timofei S. Zatsepin ◽

Ilya O. Aparin ◽

Vladimir P. Chekhonin ◽

...

Keyword(s):

Magnetic Nanoparticles ◽

Single Molecule ◽

Single Molecule Level

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Fast and easy single-molecule pulldown assay based on agarose microbeads

10.1101/2020.09.20.305177 ◽

2020 ◽

Author(s):

Qirui Zhao ◽

Yusheng Shen ◽

Xiaofen Li ◽

Fang Tian ◽

Xiaojie Yu ◽

...

Keyword(s):

Single Molecule ◽

Signal To Noise Ratio ◽

Original Method ◽

Auditory Hair Cells ◽

Single Molecule Level ◽

Cell Extracts ◽

Binding Partners ◽

Pulldown Assay ◽

Ultrahigh Sensitivity ◽

First Time

SUMMARYThe recently developed single-molecule pulldown (SiMPull) assay by Jain and colleagues is a highly innovative technique but its wide application is hindered by the high technical barrier and time consumption. We report an innovative, agarose microbead-based approach for SiMPull. We used commercially available, pre-surface-functionalized agarose microbeads to capture the protein of interest together with its binding partners specifically from cell extracts and observed these interactions under a microscope at the single-molecule level. Relative to the original method, microbead-based SiMPull is considerably faster, easier to use, and more reproducible and yet provides similar sensitivity and signal-to-noise ratio; specifically, with the new method, sample-preparation time is substantially decreased (from ∼10 to ∼3 h). These crucial features should facilitate wide application of powerful and versatile SiMPull in common biological and clinical laboratories. Notably, by exploiting the simplicity and ultrahigh sensitivity of microbead-based SiMPull, we used this method in the study of rare auditory hair cells for the first time.

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Heterostructured CuO@ZnO@Ag biomimetic setaria as wettability-switchable difunctional SERS substrate for trace pesticide and DNA detections

Nanophotonics ◽

10.1515/nanoph-2021-0179 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Chuanshen Han ◽

Yisheng Wei ◽

Fengcai Lei ◽

Shulong Zhao ◽

Yumeng Wang ◽

...

Keyword(s):

Standard Deviation ◽

Raman Scattering ◽

Single Molecule ◽

Time Domain ◽

Deoxyribonucleic Acid ◽

Limit Of Detection ◽

Sers Substrate ◽

Single Molecule Level ◽

Relative Standard ◽

Finite Different Time Domain

Abstract Wettability modification is an effective way in tailoring hotspots in surface Raman scattering (SERS) nowadays. However, due to the theoretical contradiction between hydrophobic and hydrophilic strategies, opposite views are usually put forward in building SERS structures. To realize the integration of hydrophobicity and hydrophilia in the same substrate, a wettability-switchable SERS architecture composed of heterostructured CuO@ZnO@Ag biomimetic nano Setaria (NS) has been designed and prepared in this paper. Experimentally, the structure shows impressive SERS performance under both hydrophobic and hydrophilic states. The limit of detection approaches even to single-molecule level and the lowest relative standard deviation is only ca 9.8%. Finite-different time-domain simulations and experimental analyses were systemically made to unearth the mechanism deep behind. Besides, owing to fine quantifiability, the CuO@ZnO@Ag NS shows promising potential in the detection of trace pesticide and deoxyribonucleic acid. This work provides a new idea for integrating the strategies of ‘concentration’ and ‘decentralization’, endowing SERS structure with wider application, and is also meaningful for other surface sciences.

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Rapid Kinetic Fingerprinting of Single Nucleic Acid Molecules by a FRET-based Dynamic Nanosensor

10.1101/2021.04.06.438627 ◽

2021 ◽

Author(s):

Kunal Khanna ◽

Shankar Mandal ◽

Aaron T Blanchard ◽

Muneesh Tewari ◽

Alexander Johnson-Buck ◽

...

Keyword(s):

Single Molecule ◽

Rapid Detection ◽

Limit Of Detection ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

High Specificity ◽

Digital Pcr ◽

Clinical Diagnostics ◽

Fluorescent Detection ◽

Single Molecule Level

Biofluids contain cell-free nucleic acids such as microRNAs (miRNAs) and circulating tumor-derived DNAs (ctDNAs) that have emerged as promising disease biomarkers. Conventional detection of these biomarkers by digital PCR and next generation sequencing, although highly sensitive, requires time-consuming extraction and amplification steps that increase the risk of sample loss and cross-contamination, respectively. To achieve the direct, rapid detection of miRNAs and ctDNAs with near-perfect specificity and single-molecule level sensitivity, we herein describe an accelerated amplification-free single-molecule kinetic fingerprinting. This approach, termed intramolecular single-molecule recognition through equilibrium Poisson sampling (iSiMREPS), exploits a dynamic DNA nanosensor comprising a surface anchor and a pair of fluorescent detection probes: one probe captures individual target molecules onto the surface, while the other transiently interrogates them to generate kinetic fingerprints by intramolecular sin-gle-molecule Forster resonance energy transfer (smFRET). Formamide is used to further accelerate the kinetics of probe-target interactions and fingerprinting, while background signals are reduced by removing non-target-bound probes from the surface using toehold-mediated strand displacement. We show that iSiMREPS can detect in as little as 10 seconds two distinct, promising cancer biomarkers, miR-141 and a common EGFR exon 19 deletion, reaching a limit of detection (LOD) of ~3 fM and a mutant allele fraction among excess wild-type as low as 1 in 1 million, or 0.0001%. We anticipate that iSiMREPS will find utility in research and clinical diagnostics based on its features of rapid detection, high specificity, sensitivity, and generalizability.

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Directed manipulation of membrane proteins by fluorescent magnetic nanoparticles

10.1101/2020.03.30.016477 ◽

2020 ◽

Author(s):

Jia Hui Li ◽

Paula Santos-Otte ◽

Braedyn Au ◽

Jakob Rentsch ◽

Stephan Block ◽

...

Keyword(s):

Plasma Membrane ◽

Magnetic Nanoparticles ◽

Membrane Proteins ◽

Membrane Protein ◽

Single Molecule ◽

Super Resolution ◽

Single Particle Tracking ◽

Live Cells ◽

Single Molecule Level ◽

Membrane Components

AbstractThe plasma membrane is the interface through which cells interact with their environment. Membrane proteins are embedded in the lipid bilayer of the plasma membrane and their function in this context is often linked to their specific location and dynamics within the membrane. However, few methods are available for nanoscale manipulation of membrane protein location at the single molecule level. Here, we report the use of fluorescent magnetic nanoparticles (FMNPs) to track membrane molecules and to manipulate their movement. FMNPs allow single-particle tracking (SPT) at 10 nm spatial and 5 ms temporal resolution, and using a magnetic needle, we pull membrane components laterally through the membrane with femtonewton-range forces. In this way, we successfully dragged lipid-anchored and transmembrane proteins over the surface of living cells. Doing so, we detected submembrane barriers and in combination with super-resolution microscopy could localize these barriers to the actin cytoskeleton. We present here a versatile approach to probe membrane processes in live cells via the magnetic control of membrane protein motion.

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Facial Fabrication of Large-Scale SERS-Active Substrate Based on Self-Assembled Monolayer of Silver Nanoparticles on CTAB-Modified Silicon for Analytical Applications

Nanomaterials ◽

10.3390/nano11123250 ◽

2021 ◽

Vol 11 (12) ◽

pp. 3250

Author(s):

Juanjuan Guo ◽

Yang Xu ◽

Caili Fu ◽

Longhua Guo

Keyword(s):

Single Molecule ◽

Large Scale ◽

Limit Of Detection ◽

Surface Enhanced Raman Spectroscopy ◽

Sers Substrate ◽

Self Assembled Monolayer ◽

Single Molecule Level ◽

Analytical Technique ◽

Relative Standard ◽

Surface Enhanced Raman

Surface-enhanced Raman spectroscopy (SERS) has been proven to be a promising analytical technique with sensitivity at the single-molecule level. However, one of the key problems preventing its real-world application lies in the great challenges that are encountered in the preparation of large-scale, reproducible, and highly sensitive SERS-active substrates. In this work, a new strategy is developed to fabricate an Ag collide SERS substrate by using cetyltrimethylammonium bromide (CTAB) as a connection agent. The developed SERS substrate can be developed on a large scale and is highly efficient, and it has high-density “hot spots” that enhance the yield enormously. We employed 4-methylbenzenethiol(4-MBT) as the SERS probe due to the strong Ag–S linkage. The SERS enhancement factor (EF) was calculated to be ~2.6 × 106. The efficacy of the proposed substrate is demonstrated for the detection of malachite green (MG) as an example. The limit of detection (LOD) for the MG assay is brought down to 1.0 × 10−11 M, and the relative standard deviation (RSD) for the intensity of the main Raman vibration modes (1620, 1038 cm−1) is less than 20%.

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Ferromagnetic Resonance Biosensor for Homogeneous and Volumetric Detection of DNA

10.26434/chemrxiv.5662315.v1 ◽

2017 ◽

Author(s):

Bo Tian ◽

Peter Svedlindh ◽

Mattias Strömberg ◽

Erik Wetterskog

Keyword(s):

Magnetic Nanoparticles ◽

Ferromagnetic Resonance ◽

Limit Of Detection ◽

Point Of Care ◽

Rolling Circle Amplification ◽

Resonance Field ◽

Isothermal Amplification ◽

Detection Sensitivity ◽

Serum Samples ◽

Rolling Circle

In this work, we demonstrate for the first time, a ferromagnetic resonance (FMR) based homogeneous and volumetric biosensor for magnetic label detection. Two different isothermal amplification methods, i.e., rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP) are adopted and combined with a standard electron paramagnetic resonance (EPR) spectrometer for FMR biosensing. For RCA-based FMR biosensor, binding of RCA products of a synthetic Vibrio cholerae target DNA sequence gives rise to the formation of aggregates of magnetic nanoparticles. Immobilization of nanoparticles within the aggregates leads to a decrease of the net anisotropy of the system and a concomitant increase of the resonance field. A limit of detection of 1 pM is obtained with an average coefficient of variation of 0.16%, which is superior to the performance of other reported RCA-based magnetic biosensors. For LAMP-based sensing, a synthetic Zika virus target oligonucleotide is amplified and detected in 20% serum samples. Immobilization of magnetic nanoparticles is induced by their co-precipitation with Mg2P2O7 (a by-product of LAMP) and provides a detection sensitivity of 100 aM. The fast measurement, high sensitivity and miniaturization potential of the proposed FMR biosensing technology makes it a promising candidate for designing future point-of-care devices.

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