Boosting the Electrochemical Performance of PI-5-CA/C-SWCNT Nanohybrid for Sensitive Detection of E. coli O157:H7 From the Real Sample

Abstract

Redox activity is an important indicator for evaluating electrochemical biosensors. In this work, we have successfully polymerized indole-5-carboxylic acid into poly-5-carboxyindole nanomaterials (PI-5-CA), using its superior redox activity, and introduced carboxylated single-walled carbon nanotubes (C-SWCNTs) to synthesize a composite material. Finally, a synthesized composite material was used for the modification of the glass carbon electrode to fabricate the PI-5-CA/C-SWCNTs/GCE-based immunosensor and was successfully applied for the sensitive detection of E. coli O157:H7. The fabricated immunosensor exhibited an outstanding electrocatalytic activity toward the detection of E. coli O157:H7 with a remarkably lowest limit of detection (2.5 CFU/ml, LOD = 3 SD/k, n = 3) and has a wide linear range from 2.98×101 to 2.98×107 CFU/ml. Inspired from the excellent results, the fabricated electrode was applied for the detection of bacteria from real samples (water samples) with a good recovery rate (98.13–107.69%) as well as an excellent stability and specificity. Owing to its simple preparation, excellent performance, and detection time within 30 min, our proposed immunosensor will open a new horizon in different fields for the sensitive detection of bacteria from real samples.

Electrochemical immunosensor of E. coli O157:H7 in food based on PPY-PANI and quantum dot microsphere conjugates

“…7D). Wang et al [40] prepared an immunosensor to detect E. coli O157:H7, showing a 6.7% decrease in current after 2 weeks. In the present study, the current signal decreased by 4.08% after 2 weeks, which indicated that the prepared immunosensor had good stability.…”

Plasma Functionalized Carbon Interfaces for Biosensor Application: Toward the Real-Time Detection of Escherichia coli O157:H7

“… 25 − 32 Recently, a few groups have already reported the identification of E. coli O 157 :H 7 with a limit of detection (LOD) of as low as 2–10 CFU/mL, but a lower limit of detection is still needed for bacterial analysis in food and clinical samples. 25 , 28 , 33 , 34 …”

“…25−32 Recently, a few groups have already reported the identification of E. coli O157:H7 with a limit of detection (LOD) of as low as 2−10 CFU/mL, but a lower limit of detection is still needed for bacterial analysis in food and clinical samples. 25,28,33,34 Subsequently, novel and cost-effective carbon paste electrodes comprising plasma functionalized carbon were fabricated and used as working electrodes. In addition, a robust and costeffective miniaturized E-cell was also engineered to reduce sample wastage and improve the electrochemical reversibility of the electrode.…”

“…Due to being simple, label-free, cost-effective, fast, sensitive, and specific, electrochemical sensors based on specific binding of the antigen and antibodies have emerged as excellent alternatives to traditional methods such as culture and colony-counting methods, enzyme-linked immunosorbent assays (ELISAs), surface-enhanced Raman scattering (SERS), colorimetric assays, and polymerase chain reaction (PCR) to identify pathogenic bacteria. − Recently, a few groups have already reported the identification of E. coli O 157 :H 7 with a limit of detection (LOD) of as low as 2–10 CFU/mL, but a lower limit of detection is still needed for bacterial analysis in food and clinical samples. ,,, …”