Hydrophobic Localized Enrichment of Co-reactants to Enhance Electrochemiluminescence of Conjugated Polymers for Detecting SARS-CoV-2 Nucleocapsid Proteins

Abstract

The enrichment of co-reactants is one of the keys to improving the sensitivity of electrochemiluminescence (ECL) detection. This work developed a novel hydrophobic localized enrichment strategy of co-reactants utilizing the inner hydrophobic cavity of β-cyclodextrin (β-CD). Pt nanoparticles (Pt NPs) were grown in situ on the coordination sites for metal ions of β-CD to prepare the β-CD-Pt nanocomposite, which could not only enrich co-reactant 3-(dibutylamino) propylamine (TDBA) highly efficiently through its hydrophobic cavity but also immobilize TDBA via the Pt–N bond. Meanwhile, the carboxyl-functionalized poly[2,5-dioctyl-1,4-phenylene] (PDP) polymer nanoparticles (PNPs) were developed as excellent ECL luminophores. With SARS-CoV-2 nucleocapsid protein (ncovNP) as a model protein, the TDBA-β-CD-Pt nanocomposite combined PDP PNPs to construct a biosensor for ncovNP determination. The PDP PNPs were modified onto the surface of a glassy carbon electrode (GCE) to capture the first antibody (Ab 1 ) and further capture antigen and secondary antibody complexes (TDBA-β-CD-Pt@Ab 2 ). The resultant biosensor with a sandwich structure achieved a highly sensitive detection of ncovNP with a detection limit of 22 fg/mL. TDBA-β-CD-Pt shared with an inspiration in hydrophobic localized enrichment of co-reactants for improving the sensitivity of ECL detection. The luminophore PDP PNPs integrated TDBA-β-CD-Pt to provide a promising and sensitive ECL platform, offering a new method for ncovNP detection.

Recent advances in DNA-based electrogenerated chemiluminescence biosensors

“…Nanomaterials have been used to improve the sensitivity and selectivity of DNA-based ECL biosensors for protein detection due to their better biocompatibility, easy modification of aptamers and bioenzyme activity. Chen et al 113 developed a polymeric nanomaterial luminescence cluster induced by β-Cyclodextrin (β-CD)-mediated enrichment of coreactants (Figure 9A). Contribute to the good stability and excellent ECL performance of nanocomposite material, SARS-CoV-2 nucleocapsid protein (ncovNP) can be sensitive detected by a sandwich-type immune system with detection limits down to femtomolar level.…”

Recent trends and advancements in electrochemiluminescence biosensors for human virus detection

“…Moreover, Yingying Chen et al [ 62 ] improved the sensitivity of the ECL biosensor through-reactant enrichment and used it to detect SARS-CoV2 Nucleocapsid Proteins. The combination of carboxyl-functionalized poly [2,5-dioctyl-1,4 phenylene] polymer nanoparticles (PDP PNPs) as an excellent ECL luminophore and β-cyclodextrin (β-CD)-Pt nanocomposites as ideal carriers of co-reactants (TDBA), build an attractive ECL platform and shed light on the detection of the target.…”

Bifunctional Au@Pt/Au nanoparticles as electrochemiluminescence signaling probes for SARS-CoV-2 detection

“…It differentiates from the spiked protein (S protein) by a mutation, has approximately 1000 copy numbers per viral particle and is highly conserved [ 25 ]. Therefore, N protein has great potential as a specific biomarker for diagnosis of COVID-19 and despite this, so far few immunosensors have been described for its detection [ 26 , 27 ].…”