In the ever-evolving landscape of healthcare and diagnostics, technological advancements are continuously shaping the way we approach medical testing and analysis. One such innovation that has been gaining traction in recent years is the use of lab-on-a-chip technology and microsampling techniques to revolutionize drug testing . These breakthroughs promise more efficient, less invasive, and highly accurate methods for detecting drugs in the human body, with profound implications for both patient care and clinical research. Traditionally, drug testing has often involved the collection of large blood samples or urine specimens, which can be uncomfortable, time-consuming, and sometimes challenging to administer. Moreover, such methods may not be suitable for certain patient populations, such as infants or the elderly. Lab-on-a-chip technology , however, offers a transformative solution by miniaturizing and integrating various laboratory functions onto a single chip. Lab-on-a-chip de...