Electrochemical genosensor based on carboxylated graphene for detection of water-borne pathogen

PEDOT: PSS‐grafted graphene oxide‐titanium dioxide nanohybrid‐based conducting paper for glucose detection

“…Further, KMnO 4 (6 g) dissolved in 100 ml of water was slowly added to the above solution and the solution was again stirred for 4 h. After that, the suspension was refluxed at 98°C, which resulted in the formation of a brown color solution. 20 ml H 2 O 2 was added to the brown color solution, which resulted in the color change of the solution to a bright yellow color 31 . The reduction of GO was carried out by adding GO (0.3 mg ml −1 ) with 2.28 g NaBH 4 (reducing agent) and 0.5 g CaCl 2 (catalyst) and stirred for 10 h at room temperature 32 .…”

Nanomaterial application in bio/sensors for the detection of infectious diseases

“…The developed genosensor presented higher sensitivity, ca. 2 order of magnitude when compared with resembling rGO counterpart sensor [ 115 ]. A dual aptamer sandwich complex consisting of a primary biotinylated aptamer (immobilized onto streptavidin magnetic bead) and a secondary aptamer conjugated with AgNPs was reported for the detection of S.aureus .…”

“… IS6110 DNA the sequence of Mycobacterium tuberculosis M. tuberculosis DPV 1 ×10 -15 - 1×10 -8 mol L -1 3.3 ×10 -16 mol L -1 Selective, Current response of five electrodes retained from 94.5% to 96.9% after 10 days storage Sputume [ 222 ] rGO/AuNR/polythionine AuNRs with seed growth mediated method rGO/Au NR/PT excellent electric conducting material & accelerated the electron transfer. DNA probe Human papillomavirus (HPV) DPV 1×10 -13 -1 × 10 -8 mol L -1 4.03× 10 –14 mol L -1 Selective, Sensitive, Wide linear range Human serum [ 110 ] Graphene-COOH nanoflakes, rGO COOH Graphene nanoflakes prepared from MWCNT 50nm with a wet chemical method Electrophoretic deposition of Graphene nanoflakes 2 order higher LOD than rGO, better electron transfer kinetics rather rGO DNA probe nucleic acid Escherichia coli O157: H7 EIS 10 −17 -10 −6 mol L -1 1 × 10 −17 mol L -1 15% Loss after the 6th cycle of regeneration, The 18% decrease in the signal response after 30 days [ 115 ] GO-iron oxide-chitosan hybrid nanobiocomposite Electrophoretic deposition GO-iron oxide-chitosan monodispersed spherical shape 8 to 12 fast electron transfer kinetics DNA probe E.coli EIS 10 −14 -10 −6 mol L -1 1 × 10 −14 mol L -1 Selective, 10.37, 10 % loss of the initial value after 6 cycles of regeneration &after 6-week storage [ 223 ] …”

Desenvolvimento de genossensor para a detecção precoce de câncer de cabeça e pescoço

“…Podem ser empregadas técnicas como espectroscopia de fluorescência (LOD de 13-15 pM, HPV-16 e HPV-18) (WANG; PANG; TANG, 2014), medidas magnéticas (LOD de 10 nM, HPV-18) (XU et al, 2008), e ópticas (LOD de 0,05 pmol/μL, HPV-6, HPV-11, HPV-16, HPV-18) (LI et al, 2013). Dentre os eletroquímicos (JAISWAL et al, 2018), pode-se obter baixos limites de detecção, da ordem de 10 -15 M para sequência complementar de DNA de câncer de boca (CHEN et al, 2011). Essas plataformas medem o sinal de saída por voltametria cíclica (CV), voltametria de onda quadrada (SWV), voltametria de pulso diferencial (DPV) e espectroscopia de impedância eletroquímica (EIS) (HUANG et al, 2015) , 2015).…”

“…sequência não complementar (nc-DNA) foi característico de superfícies com menor hidrofilicidade, pois as bases nitrogenadas estavam expostas na superfície(ZHANG et al, 2008). Ao contrário, para a sequência complementar (ds-DNA) apenas os grupos fosfatos estavam expostos, gerando comportamento mais hidrofílico(JAISWAL et al, 2018).Figura 11: Figura 12:…”