Fig. 8: The portable luminometric biosensor.

a The cannabinoid biosensor was configured into a portable biosensor that can be read by common equipment such as a cell phone. This biosensor workflow using the strain KM206 consists of: (1) preparing the biosensor strain by activating it with concentrated media, (2) adding the sample to be measured in the portable biosensor device, (3) adding the activated biosensor yeast to the device and incubating, (4) adding the developer solution (lysis buffer and luciferin), (5) assembling the rest of the portable biosensor device with a cellular phone, and (6) measuring biosensor output with the phone. b The portable biosensor device is assembled by attaching the sample holder disk (1) containing the activated biosensor to the adaptor ring (2) and the macrolens (4). This can then be fitted on the standard cell phone camera (3). c To validate the workflow with the device, dose–response curves were produced by incubating the strain for 3 h in the device in the presence of 30 pM–100 µM of the canonical cannabinoid THC. d Dose response obtained with 3 pM–10 µM of 11-OH-THC. e Dose response obtained with 3 pM–10 µM of the synthetic narcotic JWH-018. f Evaluation of cannabinoid concentrations by measuring light intensity in the sample well (T) and comparing with calibration points (C1–C5) of the respective compounds. Here, 150 nM THC, 150 nM 11-OH-THC or 15 nM JWH-018 (black bars) show signal intensities placing them between calibration points for 100 nM and 330 nM THC, 100 nM and 330 nM 11-OH-THC, and 10-33 nM JWH-018 (gray bars), respectively. g Detection of cannabinoids in real-life-like samples. KM206 was used to analyze reconstituted urine, serum, and saliva samples containing 100 nM (T1), 330 nM (T2), and 1 μM (T3) THC (black bars). KM206 without THC was used as negative control (C0) (gray bars). For (c–e), data presented as mean + /− standard deviation. n = 3 biologically independent samples. Source data are provided in the Source Data file.