LECTURE OF SUBJECT LECTURE 7 Dr sharafaldin Almusawi

LECTURE OF SUBJECT : LECTURE: 7 Dr. sharafaldin Al-musawi SUBJECT: Biosensors & Biochips : College of Biotecholgy LEVEL: 4 Cell-based biosensors

Cell-Based Biosensor

Cell-based biosensors Ø Cell-based biosensors utilize the principles of cell-based assays by employing living cells for detection of different analytes from environment, food, clinical, or other sources. Ø CBBs incorporate both prokaryotic (bacteria) and eukaryotic (yeast, invertebrate and vertebrate) cells. To create CBB devices, living cells are directly integrated onto the biosensor platform. Ø Usually use in biomedical fields. Ø Utilized to provide information on how a large variety of factors can affect many different types of cells.

Heavy metal whole-cell biosensors

Cell-based QCM biosensor By attachment and spreading of mammalian cells onto the solid electrode of the quartz sensor we can monitoring changes in the beating rate of cardiac myocytes due to the addition of drugs we propose a cell-based QCM biosensor. To demonstrate this the QCM method was used to monitor the mechanical contraction of cardiac myocytes.

Cell-based biosensor for disease detection Ø Impedance biosensor for measurement of immunoreaction coupled with red blood cell (RBC) amplification. (A) gold electrode surface modification by polyclonal anti-N 1 antibody. (B) H 5 N 1 virions binding and detection. (C) RBC amplification. RBCs were used as bio labels to attach to captured H 5 N 1 to amplify impedance signal by amplification of the antibody–antigen reaction.

Cell-based biosensor for toxin detection q The main advantage of using cell based biosensor for probing biotoxins and toxic agents is that cell based biosensor respond to the toxic exposures in the manner related to actual physiologic responses of the vulnerable subjects. q The results obtained from cell based biosensor are based on the toxin-cell interactions, and therefore, reveal functional information (such as mode of action, toxic potency, bioavailability, target tissue or organ, etc. ) about the toxin.

q The sensors report the cellular responses upon exposures to toxins and the resulting cellular signals are transduced by secondary transducers generating optical or electrical signals outputs followed by appropriate read-outs.

Cell-based biosensor for detection the presence or absence of specific cell • By this cell-based biosensor we can to infer the presence or absence of specific cellular environment. When cells cover the electrode the measured impedance because changes the cell membranes block the current flow.

Cell-based biosensor for detection of cancer cells A novel lectin-based suspension-cell biosensor for label-free determination of binding kinetics of protein–carbohydrate interactions on cancer cell surfaces using QCM is described. This cell-biosensor facilitates evaluation of glycosylation in real time on suspension cancer cell surfaces, where binding events take place.

Cell-based biosensor for detection of cancer cells The figure shows the results of the invasion properties of different prostate cancer cells. Prostate endothelial cells were inoculated first and spread on the electrode for 24 hours which increased the impedance to around 9, 000 Ohms. Then different cancer cells were added and the invasion of cancer cells caused the impedance to decrease to 8, 000 Ohms. The impedance after inoculating prostate cancer cells immediately decreased, showing these cells are the most invasive.