Electrical Characterization of Cellulose-Based Membranes towards Pathogen Detection in Water

Abstract

Paper substrates are promising for development of cost-effective and efficient point-of-care biosensors, essential for public healthcare and environmental diagnostics in emergency situations. Most paper-based biosensors rely on the natural capillarity of paper to perform qualitative or semi-quantitative colorimetric detections. To achieve quantification and better sensitivity, technologies combining paper-based substrates and electrical detection are being developed. In this work, we demonstrate the potential of electrical measurements by means of a simple, parallel-plate electrode setup towards the detection of whole-cell bacteria captured in nitrocellulose (NC) membranes. Unlike current electrical sensors, which are mostly integrated, this plug and play system has reusable electrodes and enables simple and fast bacterial detection through impedance measurements. The characterized NC membrane was subjected to (i) a biofunctionalization, (ii) different saline solutions modelling real water samples, and (iii) bacterial suspensions of different concentrations. Bacterial detection was achieved in low conductivity buffers through both resistive and capacitive changes in the sensed medium. To capture Bacillus thuringiensis, the model microorganism used in this work, the endolysin cell-wall binding domain (CBD) of Deep-Blue, a bacteriophage targeting this bacterium, was integrated into the membranes as a recognition bio-interface. This experimental proof-of-concept illustrates the electrical detection of 107 colony-forming units (CFU) mL−1 bacteria in low-salinity buffers within 5 min, using a very simple setup. This offers perspectives for affordable pathogen sensors that can easily be reconfigured for different bacteria. Water quality testing is a particularly interesting application since it requires frequent testing, especially in emergency situations.

Non-Invasive Biosensing for Healthcare Using Artificial Intelligence: A Semi-Systematic Review

“…Reference No. Application [179] early detection of acute myocardial infarction [178] real-time early detection of cadaverine for periodontal disease diagnostics and personalized treatment plans [176] simultaneous detection of protein biomarkers in urine in point-of-care settings [177] heart failure diagnosis with electrochemical sensor from biomarkers in saliva [180] detection of BNP biomarkers in serum [181] alternative to PCR tests to detect coronaviruses, including MERS-CoV and SARS-CoV-2 [182] detection of SARS-CoV-2 and influenza using liquid-gated graphene field-effect transistors [183] public health surveillance through pathogen detection in water [184] detection of serum amyloid A (SAA) and C-reactive protein (CRP) biomarkers…”

Century Impact of Macromolecules for Advances of Sensing Sciences

“… [ 119 ] 5 Chitosan and nickel phthalocyanine Electrical and methanol The highest sensitivity of 60.2 µS.cm and limit of detection i.e. 700 ppm [ 120 ] 6 Chitosan and graphene quantum dots Surface plasmon resonance and dopamine Excellent signal-to-noise ratio in sensing range of 0 fM–1 pM [ 121 ] 7 Cellulose Electrochemical and microbes Proof-of-concept with electrochemical detection of 10 7 colony-forming units mL − 1 [ 122 ] 8 Cellulose paper Opto-chemical for SARS-CoV-2 N protein Point-of-care application for SARS-CoV-2 surveillance [ 123 ] 9 Poly(ε-caprolactone) Organ on a chip Enhanced function of human liver [ 124 ] …”

Bicelle-based supported lipid bilayer platforms

“…An excellent application example would be the electrical biosensing where low buffer salt concentration is desired to minimize the interference of buffer ions with signal-producing ions. [113][114] The ability of bicelles to form SLB stably in low-and even no-salt conditions can be of great benefit in such scenarios, particularly in the biosensing applications that involve the use of lipid bilayer platforms for electrical detection. 115 Besides, it can be of great utility in the development of lab-on-a-chip systems and point-of-care diagnostics where minimized ionic strength in the buffer translates to maximized signal measurement.…”