Ultrasensitive and label-free electrochemical DNA biosensor based on water-soluble electroactive dye azophloxine-functionalized graphene nanosheets

In-situ fabrication of well-distributed gold nanocubes on thiol graphene as a third-generation biosensor for ultrasensitive glucose detection

“…Although thinner graphene film may arouse better performance, too thin graphene is difficult to form a non-defective surface due to the small area of single sheet [22,23]. It is required an appropriate thickness to allow the overlap between small sheets to cover the bare support.…”

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

“…Considerable efforts have focused on the modification of electrode materials with graphene and its derivatives, alone or [191] Thiolated DNA probe/G1 PAMAM * /AuNP/ graphene/Au electrode 1 pM-1 lM (1 pM) [192] ssDNA/azophloxine/graphene nanosheets/ GCE 1 fM-0.1 pM (0.4 fM) [193] ssDNA/Au nanorods/GO/GCE 0.1 fM-1 nM (3.5 fM) [194] ssDNA/Au nanorods/GO/GCE 0.1 fM-1 nM (0.035 fM) [195] ssDNA/AuNP/polyaniline/graphene sheetschitosan/GCE 10-1000 pM (2.11 pM) [196] ssDNA/AuNP-p-aminothiophenolfunctionalized GO/GCE 0.1 pM-0.1 lM (0.011 pM) [197] ssDNA/Chitosan-Co 3 O 4 nanorods-graphene/ carbon ionic liquid electrode 1 pM-1 lM (0.43 pM) [198] ssDNA/GO-chitosan/ITO 10 fM-50 nM (10 fM E.Coli O157:H7 Anti-E. coli O157:H7 Ab/AuNPs/graphene paper electrode 1.5 · 10 2 -1.5 · 10 7 cfu mL À1 (1.5 · 10 2 cfu mL À1 ) [203] Lysozyme Lysozyme binding aptamers/graphene/GCE 0.01-0.5 pM (6 fM) [204] a-fetoprotein (AFP) Ag-GO-Nafion/Au electrode 0.01-100 ng mL À1 (3 pg mL À1 ) [205] Anti-AFP Ab/Chitosan-TiO 2 -graphene/GCE 0.1-10 ng mL À1 10-300 ng mL À1 (0.03 ng mL À1 ) [206] Anti-AFP/AuNP/Prussian blue/reduced GO/ GCE 0.01-300 ng mL À1 (0.885 pg mL À1 ) [207] Anti-CEA Ab/AuNP/graphene/GCE 0.001-10 ng mL À1 (0.35 pg mL À1 ) [208] HRP/HRP-anti-CEA Ab/Au-graphene/GCE 0.1-80 ng mL À1 (0.04 ng mL À1 ) [209] Carcinoembryonic antigen (CEA) Anti-CEA Ab/chitosan/reduced GO/GCE 0.05 pg mL À1 -1 ng mL À1 (0.024 pg mL À1 ) [210] Anti-CEA/AuNP/thionine/reduced GO/GCE 0.01-300 ng mL À1 (0.650 pg mL À1 ) [207] Anti-PSA Ab/magnetic graphene nanosheets/ ITO electrode 0.003-50 ng mL À1 (0.72 pg mL À1 ) [211] Prostate specific antigen (PSA)…”

Label-free electrochemical DNA biosensor for rapid detection of mutidrug resistance gene based on Au nanoparticles/toluidine blue–graphene oxide nanocomposites

“…TB has been widely used as a feasible redox probe for electrochemical sensors due to its good chemical stability and high electrical conductivity http://dx.doi.org/10.1016/j.snb.2014. 10.059 0925-4005/© 2014 Elsevier B.V. All rights reserved. [12,13].…”

“…To date, various electrochemical DNA biosensors have been reported. To our knowledge, developing of label-free electrochemical DNA biosensors has been proved to be one successful method to directly detect target DNA [9][10][11]. As is well known, toluidine blue (TB) is a kind of phenothiazine dye and has good reversible electron transfer ability.…”