scholarly journals Breaking the barrier to biomolecule limit-of-detection via 3D printed multi-length-scale graphene-coated electrodes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Md. Azahar Ali ◽  
Chunshan Hu ◽  
Bin Yuan ◽  
Sanjida Jahan ◽  
Mohammad S. Saleh ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
High Surface ◽  
High Surface Area ◽  
Length Scale ◽  
Graphene Nanoflakes ◽  
Sensing Platform ◽  
Low Concentrations ◽  
Ultralow Concentrations ◽  
3D Printed ◽  
Coated Electrodes

AbstractSensing of clinically relevant biomolecules such as neurotransmitters at low concentrations can enable an early detection and treatment of a range of diseases. Several nanostructures are being explored by researchers to detect biomolecules at sensitivities beyond the picomolar range. It is recognized, however, that nanostructuring of surfaces alone is not sufficient to enhance sensor sensitivities down to the femtomolar level. In this paper, we break this barrier/limit by introducing a sensing platform that uses a multi-length-scale electrode architecture consisting of 3D printed silver micropillars decorated with graphene nanoflakes and use it to demonstrate the detection of dopamine at a limit-of-detection of 500 attomoles. The graphene provides a high surface area at nanoscale, while micropillar array accelerates the interaction of diffusing analyte molecules with the electrode at low concentrations. The hierarchical electrode architecture introduced in this work opens the possibility of detecting biomolecules at ultralow concentrations.

scholarly journals An Efficient Electrochemical Sensor Driven by Hierarchical Hetero-Nanostructures Consisting of RuO2 Nanorods on WO3 Nanofibers for Detecting Biologically Relevant Molecules

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3295 ◽  
Author(s):  
Hyerim Lee ◽  
Yeomin Kim ◽  
Areum Yu ◽  
Dasol Jin ◽  
Ara Jo ◽  
...  
Keyword(s):  
Tungsten Trioxide ◽  
High Surface ◽  
High Surface Area ◽  
High Sensitivity ◽  
Annealing Process ◽  
Electrochemical Sensing ◽  
Biologically Relevant ◽  
Sensing Platform ◽  
Thermal Annealing Process ◽  
Biologically Relevant Molecules

By means of electrospinning with the thermal annealing process, we investigate a highly efficient sensing platform driven by a hierarchical hetero-nanostructure for the sensitive detection of biologically relevant molecules, consisting of single crystalline ruthenium dioxide nanorods (RuO2 NRs) directly grown on the surface of electrospun tungsten trioxide nanofibers (WO3 NFs). Electrochemical measurements reveal the enhanced electron transfer kinetics at the prepared RuO2 NRs-WO3 NFs hetero-nanostructures due to the incorporation of conductive RuO2 NRs nanostructures with a high surface area, resulting in improved relevant electrochemical sensing performances for detecting H2O2 and L-ascorbic acid with high sensitivity.

scholarly journals Aptamer Conformation Switching-Induced Two-Stage Amplification for Fluorescent Detection of Proteins

Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 77 ◽  
Author(s):  
Qiao Yu ◽  
Fenfen Zhai ◽  
Hong Zhou ◽  
Zonghua Wang
Keyword(s):  
Molecular Beacon ◽  
Limit Of Detection ◽  
Low Cost ◽  
Dna Aptamer ◽  
Fluorescent Detection ◽  
Fluorescence Signal ◽  
Sensing Platform ◽  
Low Concentrations ◽  
Diagnostic Applications ◽  
Recycling Amplification

Basing on the conformation change of aptamer caused by proteins, a simple and sensitive protein fluorescent assay strategy is proposed, which is assisted by the isothermal amplification reaction of polymerase and nicking endonuclease. In the presence of platelet-derived growth factor (PDGF-BB), the natural conformation of a DNA aptamer would change into a Y-shaped complex, which could hybridize with a molecular beacon (MB) and form a DNA duplex, leading to the open state of the MB and generating a fluorescence signal. Subsequently, with further assistance of isothermal recycling amplification strategies, the designed aptamer sensing platform showed an increment of fluorescence. As a benefit of this amplified strategy, the limit of detection (LOD) was lowered to 0.74 ng/mL, which is much lower than previous reports. This strategy not only offers a new simple, specific, and efficient platform to quantify the target protein in low concentrations, but also shows a powerful approach without multiple washing steps, as well as a precious implementation that has the potential to be integrated into portable, low-cost, and simplified devices for diagnostic applications.

scholarly journals A highly sensitive safrole sensor based on polyvinyl acetate (PVAc) nanofiber-coated QCM

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kuwat Triyana ◽  
Aditya Rianjanu ◽  
Doni Bowo Nugroho ◽  
Ahmad Hasan As’ari ◽  
Ahmad Kusumaatmaja ◽  
...  
Keyword(s):  
Response Time ◽  
Polyvinyl Acetate ◽  
Limit Of Detection ◽  
High Surface ◽  
High Surface Area ◽  
Average Diameter ◽  
Promising Alternative ◽  
Force Microscopy ◽  
Atomic Force ◽  
Highly Sensitive

Abstract A novel, highly sensitive and selective safrole sensor has been developed using quartz crystal microbalance (QCM) coated with polyvinyl acetate (PVAc) nanofibers. The nanofibers were collected on the QCM sensing surface using an electrospinning method with an average diameter ranging from 612 nm to 698 nm and relatively high Q–factors (rigid coating). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to analyze the PVAc nanofiber surface morphology, confirming its high surface area and roughness, which are beneficial in improving the sensor sensitivity compared to its thin-film counterpart. The as-spun PVAc nanofiber sensor could demonstrate a safrole limit of detection (LOD) of down to 0.7 ppm with a response time of 171 s and a sensitivity of 1.866 Hz/ppm. It also showed good reproducibility, rapid response time, and excellent recovery. Moreover, cross-interference of the QCM sensor response to non-target gases was investigated, yielding very low cross-sensitivity and high selectivity of the safrole sensor. Owing to its high robustness and low fabrication cost, this proposed sensing device is expected to be a promising alternative to classical instrumental analytical methods for monitoring safrole-based drug precursors.

scholarly journals Optical-Based (Bio) Sensing Systems Using Magnetic Nanoparticles

2019 ◽  
Vol 5 (4) ◽  
pp. 59 ◽  
Author(s):  
Recep Üzek ◽  
Esma Sari ◽  
Arben Merkoçi
Keyword(s):  
Magnetic Nanoparticles ◽  
Near Infrared ◽  
High Surface ◽  
High Surface Area ◽  
Surface Enhanced Raman Spectroscopy ◽  
High Mass ◽  
Sensing Systems ◽  
Sensing Platform ◽  
Wide Range ◽  
Surface Enhanced Raman

In recent years, various reports related to sensing application research have suggested that combining the synergistic impacts of optical, electrical or magnetic properties in a single technique can lead to a new multitasking platform. Owing to their unique features of the magnetic moment, biocompatibility, ease of surface modification, chemical stability, high surface area, high mass transference, magnetic nanoparticles have found a wide range of applications in various fields, especially in sensing systems. The present review is comprehensive information about magnetic nanoparticles utilized in the optical sensing platform, broadly categorized into four types: surface plasmon resonance (SPR), surface-enhanced Raman spectroscopy (SERS), fluorescence spectroscopy and near-infrared spectroscopy and imaging (NIRS) that are commonly used in various (bio) analytical applications. The review also includes some conclusions on the state of the art in this field and future aspects.

scholarly journals Design and Manufacturing of High Surface Area 3D-Printed Media for Moving Bed Bioreactors for Wastewater Treatment

2017 ◽  
Vol 160 (1) ◽  
pp. 144-156 ◽  
Author(s):  
Olivia Elliott ◽  
Stephanie Gray ◽  
Michael McClay ◽  
Bakr Nassief ◽  
Ann Nunnelley ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Moving Bed ◽  
Printed Media ◽  
Design And Manufacturing ◽  
3D Printed

scholarly journals Modification of Microelectrode Arrays with High Surface Area Dendritic Platinum 3D Structures: Enhanced Sensitivity for Oxygen Detection in Ionic Liquids

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 735 ◽  
Author(s):  
Ghulam Hussain ◽  
Anthony O’Mullane ◽  
Debbie Silvester
Keyword(s):  
Surface Area ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
3D Structures ◽  
Surface Areas ◽  
Enhanced Sensitivity ◽  
Redox Active ◽  
Low Concentrations ◽  
One Step

Electrochemical gas sensors are often used for identifying and quantifying redox-active analyte gases in the atmosphere. However, for amperometric sensors, the current signal is usually dependent on the electroactive surface area, which can become small when using microelectrodes and miniaturized devices. Microarray thin-film electrodes (MATFEs) are commercially available, low-cost devices that give enhanced current densities compared to mm-sized electrodes, but still give low current responses (e.g., less than one nanoamp), when detecting low concentrations of gases. To overcome this, we have modified the surface of the MATFEs by depositing platinum into the recessed holes to create arrays of 3D structures with high surface areas. Dendritic structures have been formed using an additive, lead acetate (Pb(OAc)2) into the plating solution. One-step and two-step depositions were explored, with a total deposition time of 300 s or 420 s. The modified MATFEs were then studied for their behavior towards oxygen reduction in the room temperature ionic liquid (RTIL) [N8,2,2,2][NTf2]. Significantly enhanced currents for oxygen were observed, ranging from 9 to 16 times the current of the unmodified MATFE. The highest sensitivity was obtained using a two-step deposition with a total time of 420 s, and both steps containing Pb(OAc)2. This work shows that commercially-available microelectrodes can be favorably modified to give significantly enhanced analytical performances.

scholarly journals Amorphous mesoporous calcium carbonate and magnesium carbonate as effective sorbents for the removal of phosphate in aqueous solutions

2021 ◽  
Author(s):  
Eveline Croket ◽  
Michelle Åhlén ◽  
Maria Strømme ◽  
Ocean Cheung
Keyword(s):  
Calcium Carbonate ◽  
High Surface ◽  
High Surface Area ◽  
Real Life ◽  
Magnesium Carbonate ◽  
Amorphous Calcium Carbonate ◽  
Uptake Capacity ◽  
Low Concentration ◽  
Low Concentrations ◽  
Highly Porous

In this work, highly porous amorphous calcium carbonate (HPACC) and mesoporous magnesium carbonate (MMC) were tested as potential phosphate (PO43-) sorbents in water. The performance of these sorbents at a PO43- initial concentration between 0 – 1000 mg/L was evaluated. These highly porous materials were found to have enhanced PO43- uptake at low concentrations (<100 mg/L) when compared with commercial CaCO3 and MgCO3. The enhanced uptake on HPACC and MMC at low concentration was due to the high surface area and the porosity of these sorbents. The presence of NaCl salt of up to 1000 mg/L had very little effect on the performance of HPACC (<10% decreased uptake capacity), but the PO43- uptake on MMC reduced to close to zero. HPACC with its high PO43- uptake at low concentration could be relevant for real life application of PO43- ions removal from water.

scholarly journals Design and Development of 3D Printed Catalytically-Active Stirrers for Chemical Synthesis

2019 ◽  
Author(s):  
Matthew Penny ◽  
Stephen Hilton
Keyword(s):  
Chemical Synthesis ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
The Novel ◽  
Mannich Reactions ◽  
Catalytically Active ◽  
3D Printed ◽  
Novel Design ◽  
Preparation And Evaluation

<p>In this present study, we describe the novel design, preparation and evaluation of catalyst-impregnated stirrer beads for chemical synthesis. Using a low-cost SLA 3D printer and freeware design software, a high surface area holder for a magnetic stirrer bead was developed and 3D printed containing <i>p</i>-toluenesulfonic acid. The devices were used to efficiently catalyze Mannich reactions in excellent yields and it was demonstrated that the devices can be re-used up to 5-times with excellent reproducibility.</p>

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