Cu- and Sn-Codoped Mesoporous BaTiO₃-G-SiO₂ Nanocomposite for Bioreceptor-Free, Sensitive, and Quick Electrochemical Sensing of Rhizopus stolonifer Fungus

Abstract

Rhizopus stolonifer produces large postharvest losses that account for about 80% of total losses in prepackaged and loose tomato fruits from Rhizopus rot. In this study, we effectively synthesized a Cu- and Sn-codoped mesoporous BaTiO3–G–SiO2 (CuSnBTGS) nanocomposite by utilizing a simple, low-cost self-assembly method for the electrochemical detection of Rhizopus stolonifer fungus; this method does not require a biological or chemical receptor or antibodies. We focused on the microstructure design of CuSnBTGS in combination with Cu and Sn codoping, which is widely regarded as the most efficient way to produce high-performance electrodes. The resultant CuSnBTGS composite exhibited excellent electrochemical characteristics and remarkable performance in the direct detection of Rhizopus stolonifer (bread fungus) levels in contaminated solutions. The chronoamperometric response of the CuSnBTGS composite electrode was linear with Rhizopus stolonifer fungus concentrations in the 50–100 μL range, with a lower detection limit of 0.50 μL. The sensor electrode demonstrated high sensitivity, repeatability, and selectivity. The findings show that Cu- and Sn-codoped mesoporous BTGS is a viable alternative to costly electrode materials, such as gold and platinum, for amperometric sensor applications, demonstrating its applicability in the agricultural and food safety sectors.

A flexible mesoporous Cu doped FeSn–G–SiO2composite based biosensor for microalbumin detection

“…S1(a) of the ESI† shows the XPS spectrum of Cu 2p, which reveals the Cu 2p 3/2 and Cu 2p 1/2 core peaks that were produced at 932.89, 934.68 and 952.15, and 954.56 eV, respectively. 30 Fig. S1(b) of the ESI† shows the main peaks of Fe 2p 3/2 at 711.69 eV and Fe 2p 1/2 at 726.09 eV, which accord with the typical Fe 3 O 4 peaks.…”

“…13 However, significant enhancement in the response was observed for the bare CFSGS electrode after combination with mesoporous SiO 2 , because of increasing the effective surface area and facilitating the charge-transfer process. 30 These methods indicate that the combination of graphene and SiO 2 used to modify the porous structure of the CFSGS working electrode had a significant impact on the electrochemical performance. 30 In Fig.…”

“…30 These methods indicate that the combination of graphene and SiO 2 used to modify the porous structure of the CFSGS working electrode had a significant impact on the electrochemical performance. 30 In Fig. 6(c), the CFSGS CV response to microalbumin is significantly reduced, with a current density of 1.0 × 10 −5 mA cm −2 , compared to CFSG and CFS current densities of (4.0 and 5.0) × 10 −5 mA cm −2 , respectively.…”

“…The maximum mesoporous Cu-doped FeSn–G–SiO 2 (CFSGS) current response was obtained at pH 9, making it excellent for the identification of microalbumin. 30…”

“…S1(a) of the ESI † shows the XPS spectrum of Cu 2p, which reveals the Cu 2p 3/2 and Cu 2p 1/2 core peaks that were produced at 932.89, 934.68 and 952.15, and 954.56 eV, respectively. 30 25,26,31 To prove the feasibility of this biosensing strategy, the EIS was used to study the interface properties of different modied electrodes. Fig.…”