A sensitive Salmonella biosensor using platinum nanoparticle loaded manganese dioxide nanoflowers and thin-film pressure detector

• Published in: Sensors and actuators. B, Chemical Vol. 321; p. 128616
• Main Authors: Wang, Lei, Hao, Li, Qi, Wuzhen, Huo, Xiaoting, Xue, Li, Liu, Yuanjie, Zhang, Qiang, Lin, Jianhan
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.10.2020; Elsevier Science Ltd
• Subjects: Antibodies; Bacteria; Biosensors; Bluetooth; Cabs; Catalysis; Food; Hydrogen peroxide; Manganese dioxide; Manganese dioxide nanoflower; Microorganisms; Nanoparticles; Platinum; Platinum nanoparticle; Pressure biosensor; Salmonella; Salmonella detection; Sensitivity enhancement; Sensors; Smartphone App; Smartphones; Thin films; Manganese dioxide nanoflower; Salmonella detection; Pressure biosensor; Smartphone App; Platinum nanoparticle
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2020.128616

•Pt@MnO2 nanoflowers were synthesized for dual mimic enzymatic catalysis of H2O2.•Piezoresistor was combined with smartphone to real-time monitor pressure change.•This pressure biosensor was able to detect Salmonella as low as 13 CFU/mL in 1.5 h.•The mean recovery of Salmonella in the spiked chicken samples was 96.8%96.8 %. Salmonella is the leading factor for microbial food poisoning. In this study, a facile pressure biosensor was developed for rapid and sensitive detection of Salmonella using magnetic nanobeads (MNBs) to separate target bacteria, platinum nanoparticle loaded manganese dioxide nanoflowers (Pt@MnO2 NFs) to amplify detection signal, and a thin-film piezoresistor based pressure detector to monitor pressure change. First, the capture antibodies (CAbs) modified MNBs were used to specifically separate Salmonella from sample to form MNB-CAb-Salmonella complexes (magnetic bacteria). Then, the detection antibodies (DAbs) modified Pt@MnO2 NFs were used for labelling magnetic bacteria to form MNB-CAb-Salmonella-DAb-Pt@MnO2 NF complexes (nanoflower bacteria). After nanoflower bacteria were resuspended with H2O2 in a sealed centrifuge tube, H2O2 was catalyzed by Pt@MnO2 NFs to produce O2, resulting in the increase on pressure. Finally, the pressure increase was real-timely monitored by piezoresistor based pressure detector and transferred to smartphone App via Bluetooth for analysis and determination of Salmonella. This biosensor could quantitatively detect Salmonella from 1.5 × 101 to 1.5 × 105 CFU/mL in 1.5 h with low detection limit of 13 CFU/mL. The Pt@MnO2 NFs with high loading capacity of platinum nanoparticles were demonstrated as dual mimic enzymatic catalyst of H2O2 to greatly enhance the sensitivity. More importantly, it is the first time to combine a thin-film piezoresistor with a smartphone App for realtime monitoring of the pressure change resulting from the mimic enzymatic catalysis of H2O2 into O2 by the Pt@MnO2 NFs on the target bacteria to determine pathogenic bacteria in food samples.