Electrochemiluminescence immunosensor based on graphene oxide nanosheets/polyaniline nanowires/CdSe quantum dots nanocomposites for ultrasensitive determination of human interleukin-6

Critical overview on the application of sensors and biosensors for clinical analysis

“…Other current biosensors are based on electrochemistry, as shown in Table 2. For example, Liu et al [63] reported an immunosensor based on electrochemical and optical principles, with graphene oxide nanosheets, polyaniline NWs and CdSe quantum dot nanocomposites immobilized on glass carbon electrodes, to detect IL-6 in serum samples. The immunosensor exhibited long-term stability as the analytical response did not change significantly when the sensor was stored for 14 days at 4°C.…”

“…An RSD of 7.4% and good reproducibility were reported, because the detection of 10 pg mL −1 of IL-6 in five independent sensors provides an RSD of 7.6%. In addition, the analytical results of the immunosensors were compared with those of ELISA methodology, and relative deviations from −5.84% to 6.21% were found between the two methodologies, which indicates the applicability of the sensor to the determination of IL-6 levels in human samples [63]. The nanocomposite showed excellent biocompatibility, dispersability and solubility, which can improve the electrochemiluminescence biosensing method used to detect IL-6 in serum samples or other proteins in clinical samples [63].…”

Recent advances in electrochemical biosensing schemes using graphene and graphene-based nanocomposites

“…Anti-hCG antibody/multi-layer epitaxial graphene grown on silicon carbide substrates as electrode 0.62-5.62 ng mL À1 (0.62 ng mL À1 ) [212] Anti-cTnI antibody/carboxylated graphene/ Au electrode 1 pg mL À1 -1 ng mL À1 (0.1 pg mL À1 ) [213] Human serum albumin/GO/APTES-modified ITO electrode Based on detection of tumor cells 2.5 · 10 3 -1.6 · 10 5 cells mL À1 (800 cells mL À1 ) [230] Anti-b-lactoglobulin antibody/4-aminophenyl film/graphene-modified screen printed electrode 1 pg mL À1 -100 ng mL À1 (0.85 pg mL À1 ) [231] Tyrosine Phenoxy-derivatized dextran/GO/Au chip 1-20 lg mL À1 (0.39 lg mL À1 ) [232] Toxoplasma gondii antigen/AuNP/ polythionine/graphene-Nafion/GCE 0.0375-1.2 AU mL À1 2-18 AU mL À1 (8 AU mL À1 ) [233] Alanine aminotransferase Graphene field effect transistor 10-100 U L À1 [234] Cancer antigen 153 Anti-cancer antigen 153 Ab/GO/screenprinted carbon electrode 1 mU mL À1 -200 U mL À1 (0.28 mU mL À1 ) [235] IL-6 Anti IL-6 Ab/GO-polyaniline nanowires-CdSe QDs/GCE 0.5 pg mL À1 -10 ng mL À1 (0.17 pg mL À1 ) [236] Interferon c IFN-c binding aptamers/graphene/16-mercaptohexadecanoic acid-modified Au electrode 0.1-0.7 pM (0.065 pM) [237] Matrix metalloproteinase-2 (MMP-2)…”

Immunosensor with well-separated polyaniline nanowires for determination of isoelectric point based on electrochemical impedance spectroscopy

“…Therefore, by taking advantage of its intrinsic conductivity, ease of synthesis and enormous opportunities for binding biomolecules, nanostructured PANI has been utilized as a transducer material for biosensor applications [4]. For example, PANI nanowires and nanofibers combined with CdS-QDs were employed for immunosensors [5] and cytosensors [6], respectively, based on electro-chemiluminescence (ECL). Owing to the large surface area and conductive properties of PANI nanowires, label-free immunosensors [7] and DNA sensors [8] were developed using PANI as the transducer material and electrode in cyclic voltammetry and impedance measurement.…”