title: Electrochemical Aptatoxisensor Responses on Nanocomposites Containing Electro-Deposited Silver Nanoparticles on Poly(Propyleneimine) Dendrimer for the Detection of Microcystin-LR in Freshwater.
abstract: A sensitive and reagentless electrochemical aptatoxisensor was developed on cobalt (II) salicylaldiimine metallodendrimer (SDD-Co(II)) doped with electro-synthesized silver nanoparticles (AgNPs) for microcystin-LR (L, l-leucine; R, l-arginine), or MC-LR, detection in the nanomolar range. The GCE|SDD-Co(II)|AgNPs aptatoxisensor was fabricated with 5' thiolated aptamer through self-assembly on the modified surface of the glassy carbon electrode (GCE) and the electronic response was measured using cyclic voltammetry (CV). Specific binding of MC-LR with the aptamer on GCE|SDD-Co(II)|AgNPs aptatoxisensor caused the formation of a complex that resulted in steric hindrance and electrostatic repulsion culminating in variation of the corresponding peak current of the electrochemical probe. The aptatoxisensor showed a linear response for MC-LR between 0.1 and 1.1 µg·L-1and the calculated limit of detection (LOD) was 0.04 µg·L-1. In the detection of MC-LR in water samples, the aptatoxisensor proved to be highly sensitive and stable, performed well in the presence of interfering analog and was comparable to the conventional analytical techniques. The results demonstrate that the constructed MC-LR aptatoxisensor is a suitable device for routine quantification of MC-LR in freshwater and environmental samples.
authors.affiliation: SensorLab, Department of Chemistry, University of Western Cape, Robert Sobukwe Road, Bellville, Cape Town 7535, South Africa. m.bilibana@gmail.com.
authors.forename: Mawethu P
authors.initials: MP
authors.lastname: Bilibana
authors.affiliation: Department of Biological and Chemical Sciences, The University of the West Indies, Cave Hill, St. Michael BB11000, Barbados. avril.williams@cavehill.uwi.edu.
authors.forename: Avril R
authors.initials: AR
authors.lastname: Williams
authors.affiliation: SensorLab, Department of Chemistry, University of Western Cape, Robert Sobukwe Road, Bellville, Cape Town 7535, South Africa. crassie@uwc.ac.za.
authors.forename: Candice
authors.initials: C
authors.lastname: Rassie
authors.affiliation: SensorLab, Department of Chemistry, University of Western Cape, Robert Sobukwe Road, Bellville, Cape Town 7535, South Africa. csunday@uwc.ac.za.
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Sunday
authors.affiliation: SensorLab, Department of Chemistry, University of Western Cape, Robert Sobukwe Road, Bellville, Cape Town 7535, South Africa. hlamzam@gmail.com.
authors.forename: Hlamulo
authors.initials: H
authors.lastname: Makelane
authors.affiliation: SensorLab, Department of Chemistry, University of Western Cape, Robert Sobukwe Road, Bellville, Cape Town 7535, South Africa. 2724554@myuwc.ac.za.
authors.forename: Lindsay
authors.initials: L
authors.lastname: Wilson
authors.affiliation: SensorLab, Department of Chemistry, University of Western Cape, Robert Sobukwe Road, Bellville, Cape Town 7535, South Africa. 2917310@myuwc.ac.za.
authors.forename: Nomaphelo
authors.initials: N
authors.lastname: Ntshongontshi
authors.affiliation: SensorLab, Department of Chemistry, University of Western Cape, Robert Sobukwe Road, Bellville, Cape Town 7535, South Africa. 2505749@myuwc.ac.za.
authors.forename: Abongile N
authors.initials: AN
authors.lastname: Jijana
authors.affiliation: SensorLab, Department of Chemistry, University of Western Cape, Robert Sobukwe Road, Bellville, Cape Town 7535, South Africa. mmasikini@uwc.ac.za.
authors.forename: Milua
authors.initials: M
authors.lastname: Masikini
authors.affiliation: SensorLab, Department of Chemistry, University of Western Cape, Robert Sobukwe Road, Bellville, Cape Town 7535, South Africa. pbaker@uwc.ac.za.
authors.forename: Priscilla G L
authors.initials: PG
authors.lastname: Baker
authors.affiliation: SensorLab, Department of Chemistry, University of Western Cape, Robert Sobukwe Road, Bellville, Cape Town 7535, South Africa. eiwuoha@uwc.ac.za.
authors.forename: Emmanuel I
authors.initials: EI
authors.lastname: Iwuoha
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D055664:Electrochemical Techniques / Q000379:methods; D053768:Metal Nanoparticles / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D011126:Polypropylenes / Q000737:chemistry; D012834:Silver / Q000737:chemistry*
chemical_list: D011126:Polypropylenes; C443641:poly(propyleneimine); D012834:Silver
keywords: aptamer; aptatoxisensor; cyanotoxins; electrochemical biosensor; metallodendrimer; microcystin-LR; nanosensor