Skip to main content

Table 3 Biosensors with nucleic acid aptamer immobilization using noncovalent approach

From: Impact of nano-morphology, lattice defects and conductivity on the performance of graphene based electrochemical biosensors

Electrode

DNA aptamer probe [concentration]

Immobilization (buffer)

Wash and drying conditions

Analyte target [concentration]

Aptamer-analyte hybridization (buffer)

Washing and drying

Electrolyte

Stability

Reproducibility

References

DEP-GO; DEP-ERGO

THR-APT: 5′-TTT TTT TTT TTT TTT GGT TGG TGT GGT TGG-3′ [10 µM]

3 μL of THR-APT deposited onto modified electrode surface for 10 min at 60 °C in (PBS)

Wash in PBS gentle stirring

Dry at room temperature

THR [40.5 nM]

Incubated in 100 µL with THR for 60 min. at 37 °C in (Tris buffer)

Tris buffer solution at 37 °C

2×

EIS in 10 mM K3[Fe(CN)6]/K4[Fe(CN)6] in TBS (pH 8.2)

N/A

N/A

[107]

Graphene modified DEP chip

hpDNA [10 µM]

3 μL hpDNA probe drop onto modified electrode surface for 10 min at 60 °C in (TSC1)

Wash in TSC1, gentle stirring

Dry at room temperature

cDNA target [30 nM]

Incubated in 100 µL with DNA target for 30 min

at 55 °C in (TSC1)

TSC2 buffer at 42 °C 2×

EIS in 0.1 M PBS containing 10 mM K3[Fe(CN)6]/K4[Fe(CN)6]

N/A

Low for G-SL RSD = 31%

[127]

rGO-graphene double-layer electrode

Fluorescent dye labelled HIV1 gene aptamer

5ʹ-AGT CAG TGT GGA AAA TCT CTA GC-carboxyfluorescein-3ʹ [1 µM]

10 µl ssDNA probe deposited onto modified electrode surface at 35 °C for 30 min in (PBS)

Wash in nuclease free water 15×

5ʹ-GCT AGA GAT TTT CCA CAC TGA CT-3ʹ [0.01–100 nM]

Dripped 10 µL target cDNA onto electrode surface at room temperature for 1 h in (PBS)

Nuclease free water

DPV, CV in 10 mM ferricyanide aqueous solution (1 M KCl as support electrolyte)

~ 3 h

RSD = 6.2–8.1%

[135]

ERGO (DEP chip)

hpDNA: 5′-ATG GAG ACC AGG CGG CCG CAC ACG TCC TCC AT-3′ [10 µM]

hpDNA probe dry-adsorbed onto modified electrode surface at 60 °C for 10 min in (PBS)

Wash in PBS

1×

Dry at room temperature

ssDNA target: 5′-ATG GAG GAC GTG TGC GGC CGC CTG GT-3′ [0.01–10 nM; 300 nM]

Incubated in 100 µL with ssDNA target for 40 min at 55 °C in (SSC)

SSC buffer at 42 °C 2×

EIS in 10 mM of [Fe(CN)6]3−/4− as redox probe in 0.1 M PBS solution.

N/A

N/A

[108]

Graphene microarray grown by CVD

5′-AGC TTC ATA ACC GGC GAA AGG CTG AAG CT-3′ [10 µM]

10 μL DNA probe adsorbed on graphene surface for 2 h in (10 mM PBS/150 mM NaCl/50 mM MgCl2)

Wash in buffer

5′-AGC TTC AGC CTT TCG CCG GTT ATG A-3′ [5 pM to 50 nM]

Incubation in DNA target solution

N/A

N/A

CV and EIS in 1 mM K3Fe(CN)6, 1 mM K4Fe(CN)6 and 10 mM PBS

N/A

N/A

[126]