A New Psa Sensitive Probe to Be Used for Pre-Operative Assessment of Extraprostatic Extension of Tumours

Hjelme, Dag Roar; Ellingsen, R.; Falch, B.; Bjørkøy, Astrid; Østling, D.; Aune, O.; Paus, E.; Wæhre, Håkon

doi:10.1016/s1569-9056(06)60877-4

Cited by 4 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this paper, we present a novel instrument developed by InvivoSense (formerly Optomed) utilizing an interferometric technique to measure gel swelling. More specifically, a hydrogel is chemically bound to the end of an optical fiber and makes up a Fabry−Perot cavity, which optical length can be determined with high precision.…”

mentioning

confidence: 99%

Determination of Swelling of Responsive Gels with Nanometer Resolution. Fiber-Optic Based Platform for Hydrogels as Signal Transducers

2008

View full text Add to dashboard Cite

A novel technique for detection of hydrogel swelling intended for use as a chemical or biological sensor, but also generally applicable for obtaining high-precision hydrogel swelling data, is described. The underlying design principle is that a hydrogel bound to the tip of an optical fiber constituting the environmental sensing element makes up a Fabry-Perot cavity for high-resolution detection of the optical length. The interference of light guided by the optical fiber and reflected at the two interfaces, fiber-gel and gel-solution, enables optical detection of the optical path length within the gel and degree of swelling of the gel. Acrylamide-based hydrogels with various molar fractions of the cationic monomer, N-(3-dimethylaminopropyl)acrylamide, were fabricated at the end of the fiber to demonstrate the feasibility of the approach. These sensors were investigated in solutions of varying ionic strength and pH. Relative gel length changes of the approximately 50-microm half-spherical gels were determined with a precision of approximately 2 nm. Moreover, the combination of good reproducibility and resolution of determination of swelling supports measurements of ionic strength changes in the millimolar range. Kinetic measurements for gel swelling induced by changes in ionic strengths had a time constant of approximately 2 s (half-spherical gel with 60-microm radius), whereas the time constants for gel swelling induced by changes in pH were observed in the range 90-130 s. Thus, different processes dictate the swelling rate in the two different cases. The results show that hydrogel equilibrium swelling and kinetics can be determined by the optical interference method with nanometer resolution, thus providing a unique platform for characterization of hydrogels swelling in general, and using functionalized hydrogels as biological sensors in particular.

show abstract

mentioning

confidence: 99%

Determination of Swelling of Responsive Gels with Nanometer Resolution. Fiber-Optic Based Platform for Hydrogels as Signal Transducers

2008

View full text Add to dashboard Cite

show abstract

“…The complete set-up including hardware and LabView program for data collection was obtained from Invivosense ASA, Trondheim, Norway. The interferometric determination of the optical length in the hydrogel exploits a tunable super fluorescent Erdoped optical fiber source (wave-packet λ 0 = λ a − λ b = 1530-1560 nm) [61]. This IR signal used as the incident light is partly reflected at the fiber-hydrogel (reflection coefficient r 1 ) and hydrogel-immersing solution interfaces (reflection coefficient r 2 ), and a net reflected interference wave with amplitude and phase that change depending on the swelling of the hydrogel:…”

Section: Determination Of Biosensor Swelling Responsementioning

confidence: 99%

DNA Aptamer Functionalized Hydrogels for Interferometric Fiber-Optic Based Continuous Monitoring of Potassium Ions

Žuržul

Stokke

2021

Biosensors

View full text Add to dashboard Cite

In the present paper, we describe a potassium sensor based on DNA-aptamer functionalized hydrogel, that is capable of continuous label-free potassium ion (K+) monitoring with potential for in situ application. A hydrogel attached to the end of an optical fiber is designed with di-oligonucleotides grafted to the polymer network that may serve as network junctions in addition to the covalent crosslinks. Specific affinity toward K+ is based on exploiting a particular aptamer that exhibits conformational transition from single-stranded DNA to G-quadruplex formed by the di-oligonucleotide in the presence of K+. Integration of this aptamer into the hydrogel transforms the K+ specific conformational transition to a K+ concentration dependent deswelling of the hydrogel. High-resolution interferometry monitors changes in extent of swelling at 1 Hz and 2 nm resolution for the hydrogel matrix of 50 µm. The developed hydrogel-based biosensor displayed high selectivity for K+ ions in the concentration range up to 10 mM, in the presence of physiological concentrations of Na+. Additionally, the concentration dependent and selective K+ detection demonstrated in the artificial blood buffer environment, both at room and physiological temperatures, suggests substantial potential for practical applications such as monitoring of potassium ion concentration in blood levels in intensive care medicine.

show abstract

“…The cavity length, from equation (2), can be computed from the frequency of the spectral peak of the Fourier transform (FFT) of the normalized reflectance (3). Simply picking the frequency component with highest magnitude will not provide the needed accuracy, since the source bandwidth is only a few times the FSR of the Fabry-Perot sensor cavity.…”

Section: Sensor Length Estimationmentioning

confidence: 99%

“…We have used this technology for tissue PSA measurements [3] and glucose measurements [4,5]. In these earlier studies, we used readout instrumentation based on superfluorescent Er fiber source, a tunable optical fiber filter and PC based data acquisition and demonstrated nanometer length resolution from hydrogel sensors [6].…”

Section: Introductionmentioning

confidence: 99%

Low-cost high performance readout system for fiber-optic biosensors

Strømstad

Hjelme

2015

SPIE Proceedings

View full text Add to dashboard Cite

We have developed an instrument for real time continuous interferometric measurement of dimensional change in stimuli-responsive hydrogel sensors. The instrument consists of a superfluorecent LED and a low-cost grating spectrometer. All signal conditioning and processing is performed using a microprocessor. We have tested the instrument with a glucose sensitive hydrogel sensor. The rms noise on the length measurement is less than 1.4 nm, whereas rms noise on the length change is less than 0.25 nm. An observed bias of the length measurement can be reduced by minor changes in the frequency estimation algorithm used.

show abstract

A New Psa Sensitive Probe to Be Used for Pre-Operative Assessment of Extraprostatic Extension of Tumours

Cited by 4 publications

References 0 publications

Determination of Swelling of Responsive Gels with Nanometer Resolution. Fiber-Optic Based Platform for Hydrogels as Signal Transducers

Determination of Swelling of Responsive Gels with Nanometer Resolution. Fiber-Optic Based Platform for Hydrogels as Signal Transducers

DNA Aptamer Functionalized Hydrogels for Interferometric Fiber-Optic Based Continuous Monitoring of Potassium Ions

Low-cost high performance readout system for fiber-optic biosensors

Contact Info

Product

Resources

About