Ions, molecules, and bio-markers measurements using BioMEMS

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Ions, molecules, and bio-markers measurements using BioMEMS

March 22, 2016 by danutdaagmailcom

Ions, molecules, and bio-markers measurements using BioMEMS

Curator: Danut Dragoi, PhD

Small or large molecules and ions are traditionally determined in specific clinical labs facilities utilizing complex instrumentation and standard operation procedures. Same analytical clinical results can be obtained today from specialized miniaturized bioMEMS. The miniaturized instrumentation and procedures use less sample and highly sophisticated algorithms for data processing, usually intended without sample preparation or lengthy time analysis. These features reduce the costs associated with the lab work, provide rapid results to the patient and doctors. In this presentation, the talk is focused on ions, molecules, and bio-markers measurements using BioMEMS as shown in the first slide.

Slide #2

An overview of the presentation includes the items shown below.

Slide #3 shows a palm size DNA and RNA sequencer, see link in here, that I assume astronaut Scot Kelly recently used in outer space, International Space Station, to monitor his DNA and RNA changes as an effect of low gravitation and cosmic radiation, during his close to one year work in outer space. The tiny new device shown in the picture below called the MinION™, is developed by Oxford Nanopore Technologies, promises to help scientists sequence DNA in space. NASA’s Biomolecule Sequencer investigation is a technology demonstration of the device.

Slide #4

The physical principle of the DNA sequencer is based on the perturbation of the electric current that flows trough the nanopore plate when one strand of DNA macromolecule, with nucleotides attached, goes through a small pore of 5 nm diameter. In this way, by recording the electrical signals, the genetic code is revealed, see link in here.

Slide #5

The picture in slide #5 taken from here, shows how the physical principle explained before is applied.

Slide #6

The one-strip bio-sensor structure, common for glucose concentration measurements shows three layers of electrodes, see link in here, that provide an electrical signal proportional to the amount of glucose in a tiny amount of blood.

Slide #7

This slide explains the principle and the chemical reaction at the electrodes for a common glucosometer, see link in here.

Slide #8

The principle of glucosometer can be applied to other molecules, such as bio-markers that represent large molecules associated with an antigen tumor in human plasma, see link in here. Photo image below is for a portable strip reader.

Slide #9

The chemical reactions specific to a glucose meter, shown bellow, are taken from here.

Slide #10

The schematic below shows how one strip biosensor for bio-markers works, see link in here. The complexity of a bio-marker molecule requires conditional measurements for accuracy and reproducible results.

Slide #11

The schematic below is a continuation of slide #10 in which standard bio-markers are introduced in order to have a comparison between a test line and a control line besides additional antigens, gold antigen conjugate, and antibodies.Details of how all these markers interact on the strip biosensor, see link in here.

Slide #12

In this slide, which is a continuation of slides #10 and slide #11, the goat anti-mouse IgG is introduced as a control sample in the control line.

Slide #13

In many situations, one strip amperometric (electrical current) is not enough to perform the measurements, as in salt daily intake determination, see link in here.The analyte in this case is determined from the analysis of an image taken from the strips, see link in here.

Slide #14

The technique described in here, has two strips for measurements. In this way the ions in human body fluids, like Na+ can be successfully determined utilizing BioMEMS such as that described in here, and here.

Slide #15

NB-Inspired from Na+ ions determination, a possibility of similar measurements exists for K+ ions.

Slide #17

Slide #17 introduces the long range surface plasmon polariton (LRSPP) technique , which is similar to surface enhanced Raman scattering (SERS) technique. When the sample is functionalized with G protein than the interaction between components is reflected in the optical cavity power measurements, which is exploited on determining the ratio of light kappa and lambda polymeric chains.

Slide #18

The slide shows an optical plasmonic biosensor for leukemia detection, see link in here.

Slide_18

Slide #19

The schematic on slide #19 shows how specificity of protein G, human IgG kappa and lambda, goat anti-human IgG kappa and lambda as pure standards work on optical plasmonic method.

Slide#20

The output optical power of the LRSPP device versus time of introducing the analyte and the standards shows specific signal shifts for anti-human lambda IgG on HKS (high kappa serum) and anti-human kappa IgG on HKS. If the ratio of the two signal is outside of a small given range, see link in here, than the measurements indicate the presence of the cancer cells.

Slide #21

This slide shows the description of chemiluminescence method applied on a chip, see link in here, that become more popular with the development of measurements on micro-fluids using sensitive photo detectors arrays.

Slide #22

The schematic below, taken from here, shows three sections of the chip, in which tiny capillaries lines take the sample without micro-pumping using the capillary effect, separates the light molecules from the heavy, and bring them in an area where chemiluminiscent effect takes place, emitted photons detected by an array of sensitive detectors and their signal electronically processed.

Slide #23

This slide highlights the detection process that takes place towards the end of the capillary, see link in here.

Slide #24

This slide illustrates a sample of signals adapted from a photo-detector array, see link in here.

Slide #25

In conclusion, heavy analytes of bio samples can be determined with BioMEMS based chemiluminescence effect, many analyte solutions can get through a relative long capillary path using BioMEMS that are prone to miniaturization. The method of detecting photons from analyte interaction with a bioenzime-substrate with mono and multi-strips trend to be the generalization of actual R & D miniaturized devices. The new analytical micro-devices based on sensitive photo-detectors array reduces the actual costs of clinical analyzes and increases the speed of analytical process.