© 2020 Optical Society of America. This paper presents the development of a biosensor based on optical fiber, using a polyclonal antibody kisspeptin receptor as a biological recognition element that is connected to puberty onset and may also help to suppress metastasis in melanoma breast cancer. The fiber surface was chemically prepared to immobilize the antibody. The structural homogeneity of the biosensor, at each stage of the self-assembly, was characterized by Fourier transform infrared spectroscopy and by measurements of the transmission at the output of the biosensor. The morphological homogeneity analysis was performed by optical microscopy and scanning electron microscopy. The biosensor developed was checked to detect kisspeptin in brain tissues by spectral transmission using a superluminescent diode. The data were analyzed using principal component analysis. The interaction of the kisspeptin with its counterpart by means of the evolution of the transmission spectrum as a function of time was observed.