Ultrasensitive electrochemical detection of prostate-specific antigen (PSA) using gold-coated magnetic nanoparticles as ‘dispersible electrodes’

Chuah, Kyloon; Lai, Leo; Goon, Ian Y.; Amal, Rose; Gooding, J. Justin

doi:10.1039/c2cc30512g

Cited by 95 publications

(59 citation statements)

References 16 publications

(16 reference statements)

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“…Thus, developing a simple, sensitivity and reliable method to detect PSA is important for patient. Until now, several methods including enzyme-linked immunosorbent-assay (ELISA) [5], Chemiluminescent immuno-assay [6], bioluminescent immunoassay [7] and electrochemical immunoassay [8,9] have been conducted on clinical serum sample measurements. Although those methods are reliable and precise, it is time consuming, requires complex equipment and trained personal, not convenient for large-scale use in developing country [10].…”

Section: Introductionmentioning

confidence: 99%

Sandwich immunoassay for the prostate specific antigen using a micro-fluxgate and magnetic bead labels

et al. 2016

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We describe a micro fluxgate based device with rectangular magnetic core for the determination of prostate specific antigen (PSA) labeled with Dynabeads. A sandwich immunoassay was employed where PSA is captured on a gold film modified with a self-assembled monolayer of antibody. The secondary antibody is labeled with Dynabeads. By applying a DC magnetic fields in the range of 460 to 700 μT, PSA can be detected with detection limit as low as 0.1 ng mL −1 . This micro fluxgate-based assay offers the advantages of miniaturization, simple and conveniently manipulation, reusability and stability. In our perception, it offers a viable approach towards clinical determination of PSA or other biomarkers.

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Section: Introductionmentioning

confidence: 99%

Sandwich immunoassay for the prostate specific antigen using a micro-fluxgate and magnetic bead labels

et al. 2016

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“…Indeed, molecular-functionalized magneticn anoparticles loaded on the electrode interfaces can be easily removed from and then re-loaded on the electrodes urface, thus allowing magneto-switchable electrochemical processes.H owever, theses ystems are mostly useful for renewable electrode interfaces which can be easily cleaned from the used biocatalytic/ biorecognition species and reloaded with fresh species. Another application of magnetic nanoparticles can be their use as "DispersibleE lectrodes", when the nanoparticles collect analyzeds pecies in ab ulk solutiona nd then concentrate them on an electrode surface for further electroanalytical processes being attracted to the surface with an external magnetic field [95][96][97][98].A lso, biomolecularfunctionalized magnetic particles were used to amplify electrochemical analytical responses upon their rotation in ar otating magnetic field [99][100][101][102].T heir operation was similar to ar otating disk electrode [103],b ut with easy load-unload on ac onducting electrodes upport. Theu se of these systems represents mostly electroanalytical advances,b eing particularly importantf or analysis of species with low concentrations.T hese electroanalytical systems,w hile being very interesting and important for various electroanalyticala pplications,a re still not in the scope of the present review and deserves eparated iscussion.…”

Section: Discussionmentioning

confidence: 99%

Magneto‐switchable Electrodes and Electrochemical Systems

Katz

2015

Electroanalysis

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[a] 1IntroductionChemically modified electrodes [1] have been extensively developed from 1970-80s [2][3][4],m ostly for electrocatalytic applications.E xtending chemicals ystems associated with electrode surfaces to complexb iomolecular assemblies resulted in bioelectrocatalytic systems [5,6] particularly usedi ne lectrochemical biosensors [7][8][9] and biofuel cells [10][11][12].N ew applications required novel adaptive properties of electrochemicals ystems which have been realizedi nm odified electrodes functionalized with various signal-responsive materials [13,14] [29].I n the mosts ophisticated systems, the activity of switchable electrodes was controlled by complexm ulti-enzymes ystems,b eing reversibly activated-inactivated by various patterns of different biochemicals added to solutions [30][31][32],t hus mimickingb iological regulative and adaptive properties.F urther advances in the design of novel bioelectrochemical and bioelectronic systemsw ere achieved with the use of biomolecular-functionalized nano-species (nanoparticles,c arbon nanotubes,e tc.) [33][34][35].T he use of magnetic micro/nano-species( e.g.,n anoparticles,n anorods,n anosheets) [36][37][38][39][40]w as particularly important for the development of novel magneto-switchable electrodes with unique and unusual properties [25-28, 41, 42].Thep resent article overviews shortly various electrochemical systems with switchable features controlled by external magnetic field and basedo nm agnetic micro/ nano-species.A pplying magnetic field to magnetics pecies with redox, electrocatalytic or bioelectrocatalytic properties and moving them arounda llowed their different arrangements on electrode surfaces,t hus changing the electrochemical responses,s witchingt hem ON and OFF and resulting in many interestingf eatures.W hile the exact description of the exemplified systemsc an be found in the original research papers,the presentr ichly illustrated article aims at the concept explanationst os ummarize the fieldd evelopments up to date. 2Lateral TranslocationofM agnetic Micro/NanoSpecies on Electrodes and Electrode ArraysOne of the first examplesofthe magneto-switchable bioelectrochemicals ystems was basedo nalateralt ranslocation of DNA-functionalized magnetic microspheres (super-paramagnetic polystyrene beads,c a. 1 mm, with included Fe 3 O 4 nanoparticles) alonga ne lectrodea rray composed of two conducting areas ("left"a nd "right" electrodes), both with the applied potential capable of oxidizing DNAm olecules [43],F igure1.T he magnetic microspheres chemically modified with DNAo ligomers (GGC CGA CTC ACTG CG CGT CTT CTG TCC CGC Abstract:T his article is an overview of extensive research efforts in many laboratories in the last two decades in the area of magneto-switchable electrochemicals ystems. Electrochemical reactions, including electrocatalytic and bioelectrocatalytic processes,h ave been reversibly activated and inhibited upon physical translocation and reorientation of differentm agnetic micro/nano-species on electrode surfaces,p artic...

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“…Generally, surface modifications of MNPs are very important to improve their physical and chemical stability, as well as making them possess more amazing functions especially for biological application, including magnetic resonance imaging, controlled drug delivery, photothermal therapy, bio-separation and biological assays [5][6][7]. One of the most promising modifications is coating a gold shell since gold has good stability, biocompatibility, and so called "surface plasmon resonance" property.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of magnetic core-branched Au shell nanostructures and their application in cancer-related miRNA detection via SERS

et al. 2017

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Magnetic core gold shell nanostructures which integrate both SERS activity and superparamagnetism are widely utilized in SERS-based detection as SERS substrates, sample separation and preconcentration operators, as well as external magnetic field controlled directional carrier. However, most of the reported gold shells coated on the magnetic cores had smooth surfaces rather than branched nanostructures with enhanced SERS activity. Here, a novel type of Fe3O4-Au core-shell nanoparticles with branched gold shell was prepared by a seed-mediated method together with the shape induction agent AgNO3, and their growth process and mechanism, properties, as well as morphologically controlled synthesis were also investigated. The branched gold coated magnetic nanoparticles (B-GMNPs) with improved SERS performance were further utilized to build superparamagnetic and SERS-active capturers by assembling tetrahedral DNA onto their surfaces for sandwich-structured detection of cancer-related biomarker miRNA-21. The experimental results indicate that highly sensitive and specific detections can be obtained by the proposed SERS sensing system including B-GMNPs and tetrahedral DNA, and the limit of detection (LOD) of miRNA-21 in serum is 623 amol L −1 . These B-GMNPs can be used as good SERS substrates with the functions of external magnetic field controlled sample separation and directional enrichment for effective SERS-based biochemical sensing and detections.

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Ultrasensitive electrochemical detection of prostate-specific antigen (PSA) using gold-coated magnetic nanoparticles as ‘dispersible electrodes’

Cited by 95 publications

References 16 publications

Sandwich immunoassay for the prostate specific antigen using a micro-fluxgate and magnetic bead labels

Sandwich immunoassay for the prostate specific antigen using a micro-fluxgate and magnetic bead labels

Magneto‐switchable Electrodes and Electrochemical Systems

Synthesis of magnetic core-branched Au shell nanostructures and their application in cancer-related miRNA detection via SERS

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