Simultaneous and Sensitive Determination of Amphetamine, Codeine and Morphine in Exhaled Breath Condensate, Using Capillary Electrophoresis Coupled with On-line and Off-line Enhancing Methods

A near-infrared plasmonic biosensor for detection of morphine and codeine in biological samples based on the end-to-end assembly of modified gold nanorods

The analytical determination of opiates in biological samples is a critical mission and remains a challenge for almost all judicial and clinical drug testing panels due to their high abuse potential. Based on the high sensitivity of the longitudinal surface plasmon resonance (LSPR) peak of gold nanorods (AuNRs), we successfully developed a novel and simple refractive index sensing platform for detection of morphine (MOR) and codeine (COD) by means of 2-amino-5-mercapto-1,3,4-thiadiazole functionalized gold nanorods (AMTD-AuNRs) in aqueous solution, which is, to the best of our knowledge, the first report on the assay of MOR and COD using AuNRs. AMTD molecules strongly anchor onto the tips of AuNRs via the mercapto group and subsequent hydrogen-bonding interactions between AMTD and the analytes induced end-to-end chain assembly of AuNRs and a consequent decrease of the LSPR absorption band at 850 nm along with a bathochromic shift and emergence of a new hybridized plasmon mode at 1050 nm which was characterized using a Vis-NIR spectrophotometer. After systematic optimization, the absorbance ratio (A1050/A850) was proportional to the concentration of MOR in the ranges of 0.08-5 μM and 0.2-8 μM for COD without any significant effect from possible interferents. Furthermore, detection limits of 40 and 62 nM were achieved for MOR and COD, respectively, which are much lower than the cut-off level of 2000 ng mL-1 for opiates in urine samples set by the Substance and Abuse Mental Health Services Administration (SAMHSA). Eventually, as proof-of-applicability, human urine and blood serum samples spiked with MOR and COD were analyzed and excellent recoveries ranging from 94.4 to 108.9% were obtained, demonstrating the successful applicability of the designed refractive index probe in real biological specimens.

A Review of Analytical Methods for Codeine Determination

Codeine is derived from morphine, an opioid analgesic, and has weaker analgesic and sedative effects than the parent molecule. This weak opioid is commonly used in combination with other drugs for over-the-counter cough relief medication. Due to the psychoactive properties of opioid drugs, the easily obtained codeine often becomes subject to misuse. Codeine misuse has emerged as a concerning public health issue due to its associated adverse effects such as headache, nausea, vomiting, and hemorrhage. Thus, it is very important to develop reliable analytical techniques to detect codeine for both quality control of pharmaceutical formulations and identifying drug misuse in the community. This review aims to provide critical outlooks on analytical methods applicable to the determination of codeine.