Data from: Aptamer-Based QCM-D Platform for Monitoring Biofertilizers in Soil

The increasing use of bioinoculants to enhance soil quality and crop productivity requires efficient sensor platforms for fast monitoring. EU and national registration demand analytical methods to evaluate environmental fate and long-term effectiveness. Addressing these challenges requires evaluating bioinoculant persistence and impact on microbial communities, emphasizing the need for reliable detection methods in soil.

This study presents an aptamer-based sensing platform using Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) to detect microbial inoculants, establishing the basis for portable sensors. The QCM-D platform is functionalized with single-stranded DNA (ssDNA) aptamers specifically designed to detect Bacillus subtilis strains. Specificity and selectivity are evaluated using inactivated B. subtilis in buffer and compared with negative controls (P.protegens and mixed samples). One aptamer shows outstanding specificity, achieving a limit of detection (LoD) of 10⁵ CFU/ml.

The platform is applied to inoculated soil to validate its performance in real matrices. Two distinct soils are tested: sandy soil from Poland (neutral pH) and medium-textured sandy loam soil from Germany (sub-alkaline pH). An optimized bacterial extraction technique is developed to produce samples compatible with QCM-D. Results demonstrate that the platform maintains high specificity and sensitivity across both soil types, confirming its robustness for on-site monitoring of microbial inoculants.