Electrochemical DNA Biosensors for Analysis of Selective Estrogen Receptor Modulators (SERM) Raloxifene

Raloxifene (RLX) is a selective estrogen receptor modulator (SERM) used in cancer treatment. Estrogen receptors exist in two different forms: alpha and beta. SERM compounds bind to these receptors and exert both antagonist and agonist effects. These nonsteroidal compounds induce estrogen agonistic and antagonistic effects in certain tissues by utilizing their three-dimensional conformation. The most well-known SERMs are RLX and tamoxifen (TAM). This study investigated the interaction between RLX and DNA using a single-use electrochemical biosensor. Initially, the electrochemical behavior of RLX was examined in aqueous solutions within a pH range of 2.0–12.0 using cyclic and square wave voltammetry. The detection limit of RLX was calculated as 5.63 µM (2.66 µg mL⁻¹) (with a linearity range between 1.25 and 50 µg mL⁻¹). Additionally, an electrochemical biosensor was designed using a pencil graphite electrode (PGE) to facilitate the interaction between RLX and DNA sequences. As a result, the developed biosensor provided a suitable platform for the precise analysis of RLX–DNA interactions. In this study, the interaction of the anticancer drug with DNA-modified electrodes was investigated. The binding mechanism of RLX to DNA was determined using electrochemical voltammetry techniques. DNA-modified electrodes were prepared and exposed to RLX, followed by electrochemical analysis to measure the interaction. In summary, it was demonstrated that single-use electrochemical biosensors enable label-free detection of RLX–DNA interactions with high sensitivity, faster processing, and less labor-intensive techniques.