A novel and highly selective aptamer-based sandwich-type biosensor assisted by second-order calibration methods for efficient biosensing of Streptococcus pneumoniae

In this article, a novel electrochemical biosensor was fabricated based on modification of a screen printed carbon electrode (SPCE) with 5′-GTT GGAATG CTG AGA AAA AAA AAA-Thiol-C3-3' (CAP)/lead nanoparticles/fullerene C60-multiwalled carbon nanotubes with the aim of biosensing of the Streptococcus pneumoniae (SPP). Single stranded DNAs extracted from the SPPs were used as targets (TAGs) which were captured by the CAPs, and by 5′-6-Fam-AAAAAC GGT TGAACT GAT TG-3' (APT) formed an APT-TAG-CAP sandwich assay for the detection of single stranded DNAs of the SPP. The differential pulse voltammetric (DPV) response of the biosensor immersed into the electrochemical probe solution was changed upon formation of the APT-TAG-CAP sandwich assay which was used to the determination of the number of the SPPs. In order to increase the selectivity of the biosensor towards determination of the number of the SPPs, it was assisted by second-order calibration methods based on generation of second-order DPV data, data pre-processing, trouble shooting, and data analysis by U-PLS/RBL (sensitivity: 22 ​μA ​(ng/μL)-1 single stranded DNA/22 ​μA (283 SPPs)-1 and LOD: 0.1 ​ng/μL single stranded DNA/28 SPPs) and N-PLS/RBL as well-known second-order algorithms. The biosensor assisted by U-PLS/RBL showed a better performance towards determination of the SPP whose performance was comparable with the NanoDrop method as reference method. •A novel aptamer-based sandwich-type biosensor was fabricated based on modification of a SPCE for determination of the number of the SPPs.•To develop a selective biosensor, it was assisted by three-way calibration methods.•Second-order DPV data were generated at different pulse heights.•Two three-way calibration models using U-PLS/RBL and N-PLS/RBL were developed.•The biosensor assisted by U-PLS/RBL was successful in determination of the number of the SPPs.