Determination of Progesterone (P4) from bovine serum samples using a microfluidic immunosensor system

FERNANDO JAVIER ARÉVALO; GERMÁN ALEJANDRO MESSINA; PATRICIA GABRIELA MOLINA; MARÍA ALICIA ZÓN; JULIO RABA; HÉCTOR FERNÁNDEZ

TALANTA

ELSEVIER SCIENCE BV

Año: 2009 vol. 80 p. 1986 - 1992

0039-9140

ABSTRACTProgesterone (P4) is a steroidal hormone with a vital role in the maintenance of humanand animal health. This paper describes the development of an immunosensor coupledto glassy carbon (GC) electrode and integrated to a microfluidic system to quantify P4from bovine serum samples in a fast and sensitive way. The serum samples spiked witha given P4 concentration and a given P4 concentration bound to horseradish peroxide(HPR) were simultaneously added and, therefore, they competed immunologically withsheep monoclonal anti-P4 antibodies that were immobilized at a rotating disk. HRP inthe presence of hydrogen peroxide (H2O2) catalyzes the chatecol (H2Q) oxidation tobenzoquinone (Q). Its reverse electrochemical reduction to H2Q can be detected at a GCelectrode surface at −0.15V by chronoamperometric measurements. These currentresponses are proportional to the enzyme activity and inversely proportional to the P4amount present in bovine serum samples. This P4 immunosensor showed a linearworking range from 0.5 to 12.5 ngmL−1. The detection (DL) and quantification (QL)limits were 0.2 and 0.5 ngmL−1, respectively. The electrochemical immunosensor had ahigher sensitivity than the ELISA method using conventional spectrophotometricdetections. However, both methods allowed us to obtain similar detection limits. Theimmunosensor allowed us to make up to 100 determinations on different sampleswithout any previous pre-treatment. This behavior proved to be suitable to detect P4 inroutine veterinary, clinical, biological, physiological, and analytical assays.