Development of an aptasensor for highly sensitive detection of cardiac troponin I using cobalt-nickel metal-organic framework (CoNi-MOF)

Abstract

Objective and rationale: This study aimed to develop a highly sensitive and selective single-stranded DNA (ssDNA) aptamer targeting cardiac troponin I (cTnI), a crucial biomarker for acute myocardial infarction (AMI). The objective was to fabricate a novel aptamer electrochemical sensor using a composite material of cobalt-nickel metal-organic framework (CoNi-MOF) on screen-printed carbon electrodes (SPCE), leveraging the composite's large surface area and excellent electrical conductivity alongside the aptamer's high affinity for cTnI.

Methods: The aptamer electrochemical sensor was fabricated using the CoNi-MOF composite on SPCE and characterized its properties. They conducted electrochemical measurements to assess the sensor's performance in detecting cTnI. The sensor's stability, reproducibility, and electro-catalytic activity were evaluated.

Results: The sensor demonstrated linear detection of cTnI over a concentration range of 5-75 pg/mL, with a low limit of detection (LOD) of 13.2 pM. Remarkable stability and reproducibility were observed in cTnI detection. The sensor exhibited exceptional electro-catalytic activity, enabling accurate quantification of cTnI levels in various solutions.

Conclusions: This research presents a significant advancement towards the development of reliable, cost-effective, and easily deployable cTnI sensors for clinical applications. The sensor's versatility in detecting cTnI across different concentration ranges highlights its potential utility in diverse clinical settings, particularly for early detection and monitoring of cardiac conditions.

Keywords: Aptamer; Cardiac troponin; Diagnostic sensor; Electrochemical; Metal-organic framework.

Graphical abstract

Scheme 1

Schematic representation of aptamer based electrochemical detection of Cardiac Troponin-I.

Fig. 1

XRD pattern for CoNi-MOF.

Fig. 2

Raman spectra of CoNi-MOF.

Fig. 3

FT-IR Spectra profile of CoNi-MOF.

Fig. 4

(a–b) FE-SEM image of CoNi-MOF, (c–h) colour mapping results of CoNi-MOF, (c) mixed colour mapping, (d–h) mapping results of C, N, O, Ni and Co respectively.

Fig. 5

CV of Bare SPCE, CoNi-MOF/SPCE and AcTnI/CoNi-MOF/SPCE in 50 mV/s Scan rate.

Fig. 6

EIS characterisation of bare SPCE(black), CoNi-MOF/SPCE(red), AcTnI/CoNi-MOF/SPCE(green).

Fig. 7

The role of (a) AcTnI concentration and (b) incubation duration on sensing efficiency.

Fig. 8

a) DPV curves of AcTnI/CoNi-MOF/SPCE in relation to 5 pg/ml, 10 pg/ml, 15 pg/ml, 25 pg/ml, 50 pg/ml, and 75 pg/ml (b) Linear correlation between current and logarithm of cTnI concentrations.

Fig. 9

Selectivity evaluation of the sensor.