Approximately 4% of women of reproductive age are estimated to suffer from premenstrual dysphoric disorder (PMDD), a condition likely underdiagnosed due to various biases, suggesting that actual prevalence may be higher. Addressing this, a novel electrochemical sensor was developed using a screen-printed electrode of reduced graphene oxide modified with a Cu(II) triazole complex, Cu(LNO2)2/rGO/SPCE. This sensor aims to determine levels of serotonin and 17 beta-estradiol rapidly, and simultaneously, key analytes implicated in PMDD. The method demonstrated high sensitivity for both analytes, achieving sensitivity levels of 0.064 mu A/mu mol L-1 for serotonin and 0.055 mu A/mu mol L-1 for 17 beta-estradiol, with a linear detection range of 2 to 42 mu mol L-1. Detection limits were 42 nmol L-1 for serotonin and 53 nmol L-1 for estrogen. The sensor also exhibited high stability and selectivity against common interferents found in biological fluids. It was successfully used to measure serotonin and 17 beta-estradiol in human serum and urine, with recovery percentages within the expected ranges. This demonstrates that the sensor proposed in this work holds significant potential to contribute not only to the accurate diagnosis of such disorders but also to their treatment. We hope that this research will pave the way for the development of devices that have a positive impact on the quality of life of women suffering from multisystem diseases caused by hormonal malfunctions.