Table 4.
Biosensors with nucleic acid aptamer immobilization covalent approach
| Electrode | Electrode surface Activation | DNA aptamer probe (size) sequence [concentration] | Electrode surface Immobilization | Analyte target [concentration] | Aptamer-Analyte Nucleic acid Hybridization | Electrolyte | Stability | Reproducibility | References |
|---|---|---|---|---|---|---|---|---|---|
| DEP chips GCE | 0.05 M EDC (3 µL) and 0.03 M sulfo-NHS in PBS (pH 7) for 1 h to activate carboxyl acid groups. PBS wash |
DNA (26 base) 5′-NH2-(CH2)6-ACCAGGCGGCCGCACACGTCCTCCAT-3′ [N/A] |
3 µL DNA probe at optimized concentration deposited overnight in humidified air at RT in PBS (pH 7) |
5′-ATG-GAGGACGTGTGCGGCCGCCTGGT-3′ N/A |
Incubated with gentle stirring in 100 µL with DNA target for 30 min at 42 °C in (TSC1 buffer) |
CV and EIS in 0.01 M PBS buffer containing K3[Fe(CN)6]/K4[Fe(CN)6] (10 mM) 1:1 molar ratio |
N/A | N/A | [136] |
| GCE/rGO/AMEL | 0.2 M EDC in MES buffer and 0.5 M NHS in 0.1 M PBS treatment for 1 h to activate carboxyl acid groups of rGO. PBS wash |
AMGX (17 base) 3′-TATCCC AGATGT TTCTC-NH2-5′ [1 µM] |
80 µL DNA probe dispensed on inverted surface covered with a glassy cap of for 1 h at 25 °C | AMGX: 3′-GAGAAACATCTGGGATA-5′ [10 zM–10 fM] | With PCR | 0.5 mM [Fe(CN)6]3−/4− in 0.1 M KCl | 3 days | RSD = 5.014% | [48] |
| Anodized epitaxial graphene electrode | 0.2 M EDC and 0.5 M NHS for 1 h. Rinsed with ultra-pure water |
DNA (30 base) NH2-C12-5′-GCACCTGACTCCTTGGAGAAGTCTGCCGT-3′ [N/A] |
DNA solution added and incubated overnight | 5′-ACG GCA GAC TTC TCC ACA GGA GTC AGG TGC-3′ [50 fM–1 µM] | Electrode treated with 100 μL ssDNA target solution for 40 min at 42 °C | EIS in PBS/14 mM NaCl/0.27 mM KCl/1 mM Na3PO4 and 0.176 mM K3PO4) | N/A | 7% for 1 nM | [137] |
| MnTPP/rGO-GCE | 20 mM EDC and 32 mM NHS in 10 mM PBS for 1 h at room temperature |
ssDNA (25 base) NH2-C6-5′-TCAATCTCG GGAATCTCA ATGTTAG-3′ [1 µM] |
Add a solution of ssDNA probe for 1 h at room temperature in the activation solution |
5′-CTAACATTG AGATTCCCGAGATTGA-3′ [100 aM–1 nM] | 5 μL DNA target deposited for 40 min at 47 °C. | 0.1 M KCl with 5 mM [Fe(CN)6]3−/[Fe(CN)6]4− | High | RSD < 3% | [138] |
| Gold-wire electrode (AuE) | N/A |
Thiol-ssDNA (23 base) 5′-SH-(CH2)6-AGTCAGTGT GGAAAATCT CTAGC-3′ [N/A] |
2 µL of ssDNA dropped on AuE surface and kept 15 min in water at room temperature. Then immersed in dispersed graphene for 15 min |
DA [1–50 nM] | N/A | DPV in 0.2 M of PBS buffer (pH 7.4) | 1 week; 90% in 2 weeks | 3.5% for 1 µM DA | [139] |
| MoS2/graphene/GCE | N/A |
DNA (15 base) 5′-AGTGATTTT AGAGAG-3′ [1 µM] |
20 µL pDNA dropcast on MoS2/graphene/GCE. Dried in oven for 35 min at 57 °C | 5′-TCA CTA AAA TCT CTC-3′ [0.1–100 fM] | 20 µL cDNA dropcast on GCE, dried for 30 min at 57 °C. Treated with 1 M KCl solution 0.2 M K3[Fe(CN)6] at - 0.7 V for 300 s to release the dsDNA. | 1.0 M KCl solution containing 0.2 M K3 [Fe(CN)6] at a scan rate of 0.10 V/s from 0.6 to − 0.3 V | N/A | N/A | [140] |
| AuNP/graphene–VS2/GCE | N/A |
DNA (S1) (21 base) 5′-HS-(CH2)6-TTGCCCGTTTACTTTGGGTCT-3′ [9.6 µM] |
AuNPs/grapheneVS2/GCE was incubated in HS-DNA for 3 h at room temperature | 5′-AGA CCC AAA GTA AAC GGG CAA-3′ [0.5–500 pM] | Immersion of the electrode into target DNA at room temperature for 60 min | 1 mmol/L [Fe(CN)6]3−/4− containing 0.1 mol/L KCl | 92.1% after 1 week | RSD = 4.3% | [141] |
| GO-PGE | N/A |
HBV DNA probe: (20 base) 5′-NH2-(CH2)6-AATACCACA TCATCCATA TA-3′ [40 µg/mL] |
GO-PGEs were immersed in 110 µL of amino linked HBV probe solution prepared in ABS for 1 h | 5′-TAT ATG GAT GAT GTG GTA TT-3′ [160 µg/mL] | Probe immobilized electrodes immersed in 110 µL target for an hour | EIS in 2.5 mmol/L K3[Fe(CN)6]/K4[Fe(CN)6] (1:1) with 0.1 mol/L KCl DPV in ABS | N/A | RSD = 14.2% | [142] |
| GQD-PGE | N/A |
ssDNA-1 (35 base): 5′-TCTCTCAGT CCGTGGTAG GGCAGGTTG GGGTGACT-3′ [500 nM] |
Electrode immersed in 70 μL 10 mM Tris–HCl buffer containing ssDNA-1 for 1 h | 5′-AG TCA CCC CAA CCT GCC CTA CCA CGG ACT GAG AGA-3′ [100–500 nM] | Target first added to solution of ssDNA-1 and incubated for 1 h before the immobilization | DPV in 10 mM tris–HCl buffer solution containing 5 mM [Fe(CN)6]3−/4− pH 6 | N/A | N/A | [143] |
| GCE-APTES-rGO | N/A |
MRSA DNA probe (30 base) 5′-ATGATTATG GCTCAGGTA CTGCTATCC ACC-3′ [10 µM] |
5 μL DNA dropped onto GCE-APTES-rGO electrode then capped with a centrifuge tube and kept at room temperature for 6 h | 5′-GGT GGA TAG CAG TAC CTG AGC CAT AAT CAT-3′ [10 µM] | 5 μL target DNA solution dropped onto GCE’s and droplet kept at room temperature for 30 min | 0.1 M KCl containing 5 mM [Fe(CN)6]3−/4− (1:1) | N/A | N/A | [144] |
| PTCA/CCG-GCE |
200 mM EDC and 50 mM NHS in MES buffer cast on PTCA/ CCG-GCE surface to activate the carboxyl group for 1 h. Rinsed with 10 mm Tris buffer (pH 7.4) |
AS1411 (32 base) 5′-GGTGGT GGTGGTTGT GGTGGTGGT GGTTTTTT-NH2-3′ [1 µM] | DNA dropcast on the surface and then incubated for 4 h |
Cancer cells [1 µM] |
The surface was washed by buffer and subsequently hybridized with aptamer DNA in 10 mM Tris, 2.5 mM MgCl2, 140 mM KCl (pH 7.4) for 1 h | CV in 10 mM K3[Fe(CN)6], 1.0 M KCl; EIS in 10 mM K3[Fe(CN)6]/K4[Fe(CN)6] (1:1) mixture with 1.0 M KCl | N/A | N/A | [145] |