MicroCantilever (MC) based sensors can provide revolutionary sensitivity for forensic detection and identification of controlled substances, toxic species, biological molecules and DNA matching. Current sensor systems require extensive sample preparation and/or specialized instrumentation to identify molecules of controlled substances such as cocaine with high specificity and sensitivity. The authors aim to overcome the limitations of current sensor systems by developing a novel sensing approach based on MC sensors coupled with aptamer-based receptor layers. To demonstrate the feasibility and forensic suitability of their approach, the authors developed sensors for sensitive and specific identification of cocaine, cocaine metabolites, and methamphetamine and metabolites. These objectives were accomplished through the completion of tasks arranged in two phases so that knowledge and experience gained in the first phase may be utilized for successful completion of the second phase. In the first phase of the project, presented in this report, the authors: 1) Optimized the available DNA aptamer to improve its sensitivity for binding with cocaine; 2) Characterized the sensitivity and specificity of MC-based sensors functionalized with an available DNA aptamer that has specific affinity for cocaine; and 3) Initialed the selection of additional variant DNA aptamers with selective sensitivities to cocaine and its metabolites.