Chemical Sensors for Radiopharmaceuticals

Voltammetry of [Re(DMPE)3]+ at Ionomer-Entrapped Composite-Modified Electrodes

“…Radiopharmaceuticals are routinely used for organ imaging and for radiotherapy in nuclear medicine. One of the fundamental problems associated with the use of radiopharmaceuticals is that, in many circumstances, the composition of an injected radiopharmaceutical is known, but the chemical form of the agent that is actually responsible for the imaging or therapy may be an altered form due to in vivo reactions . This is evidenced by biological studies which show that in vivo redox reactions can markedly affect the biodistributions of technetium-99m and rhenium-186 radiopharmaceuticals. , Therefore, gaining the information regarding the chemical form that is responsible for imaging or therapy is crucial for developing more efficacious radiopharmaceuticals.…”

Spectroscopic and Electrochemical Evaluation of a Perfluorosulfonated Ionomer and Its Gel as Preconcentrating Media for [ReI(DMPE)3]+, Where DMPE = 1,2-Bis(dimethylphosphino)ethane

“…A change in oxidation state of the metal ion that alters the overall charge of the complex can have a deleterious effect on organ imaging, and, consequently, in vivo redox reactions of an imaging agent are of concern. One possible way to monitor in vivo redox reactions of a radiopharmaceutical compound is with an electrochemical or an optical sensor. , The in vivo concentrations of imaging agents are typically very low, which might preclude detection of these compounds at bare electrode or optical fiber surfaces. A polymer-modified surface, however, would have an advantage over a bare surface if an appropriate polymer could be found that would enhance the electrochemical or optical signal of the radiopharmaceutical by preconcentrating it at the sensor surface, thus facilitating its detection at low concentration.…”

Electrochemical Behavior of [ReI(DMPE)3]+, Where DMPE = 1,2-Bis(dimethylphosphino)ethane, at Perfluorosulfonated Ionomer-Modified Electrodes

“…In vivo monitoring of a radiopharmaceutical with a chemical sensor after injection into a test animal would provide a means of obtaining valuable information about the fate of an imaging agent after injection. Sensors implanted in specific organs of interest in order to determine the chemical form(s) of the radioactive complex that is accumulating in an organ would be especially useful for developing improved radiopharmaceuticals . In order to accomplish this goal, sensors for in vivo monitoring of Tc/Re complexes that are used in nuclear medicine are being developed.…”

“…Since many imaging agents are electroactive and absorb light in the UV−visible range, both electrochemical and optical sensors are being considered . The optical sensors are based on the measurement of absorbance with a fiber optic .…”