Abstract: Methods and systems for assessing plant conditions by volatile detection. The subject matter of the present disclosure describes a cost-effective, compact, noninvasive volatile organic compound (VOC) fingerprinting platform installed on a consumer electronics device such as a smartphone, tablet, or handheld device, or other mobile device for the early detection and/or diagnosis of disease in a plant caused by infection by a plant pathogen such as Altemaria solani, Septoria lycopersici, or Phytophthora infestans, based on the pattern analysis of characteristic leaf volatile emissions. This handheld device integrates a sensor array to be imaged by the smartphone camera and a micropump for active sampling and real-time detection.

Abstract: Methods of extracting analytes of interest from biological samples including soft plant tissues (e.g., plant leaves) or animal tissues are described. The methods include contacting the biological samples with a microneedle that absorbs the analyte of interest. Related systems and methods of detecting pathogens or pests or of genotyping the plant or animal from which the biological sample is derived are described. Also described are methods of delivering a substance of interest (e.g., a pesticide) to a plant by contacting a soft plant tissue with a microneedle coated with the substance of interest.