原子力显微镜探针

Plant-Growth Synchronized, Acid Phosphatase-Responsive Lignin-Based Controlled Release Phosphorus Nanofertilizers

Developing smarter fertilizer systems that deliver nutrients when and where plants need them could help improve nutrient efficiency while reducing unnecessary losses to the environment. In this article, Alice Boarino, Nicola Carrara, Joaquin Clua, Nick Zahnd, Yves Poirier, and Harm-Anton Klok present a lignin-based nanofertilizer platform designed to respond to a biological signal associated with phosphate deficiency in plants.

The researchers developed tripolyphosphate (TPP)-cross-linked lignin nanoparticles engineered to release phosphorus in response to acid phosphatase. This enzyme is upregulated by plants under phosphate-starvation conditions, providing a mechanism for synchronizing nutrient release with plant demand. The lignin/TPP nanoparticles therefore combine a biodegradable polymer-based carrier with an enzyme-responsive release mechanism rather than relying on a conventional uncontrolled release process.

The nanofertilizers were prepared from aminated lignin and tripolyphosphate through ionic gelation followed by covalent cross-linking. The resulting nanoparticles were investigated to determine their structural and functional properties and to understand how exposure to acid phosphatase affects their stability. The authors found that phosphorus release was triggered by acid phosphatase activity and occurred together with nanoparticle disintegration, demonstrating the responsiveness of the lignin-based delivery system to the targeted enzymatic stimulus.

The biological experiments further demonstrated the potential of the nanoparticles as a phosphorus source for Arabidopsis thaliana. Treatment with lignin-TPP nanoparticles suppressed the growth inhibition and molecular responses normally associated with phosphate deficiency, supporting their potential as controlled-release nanofertilizers for plant growth and development.

Atomic force microscopy (AFM) was used to characterize the morphology and size distribution of the lignin-based nanoparticles. AFM imaging was performed in tapping mode using a NanoWorld PointProbe® NCSTR-50 AFM probe, an aluminum-coated silicon cantilever with a spring constant of 7.4 N/m and a resonance frequency of approximately 160 kHz.

For AFM analysis, nanoparticle dispersions were deposited onto cleaned silicon wafers and dried overnight at room temperature. Samples prepared in Milli-Q water were used to characterize nanoparticle dimensions, while dispersions in MES buffer were used to investigate the effect of acid phosphatase on nanoparticle stability. The resulting AFM images enabled direct nanoscale characterization of the particles, with nanoparticle sizes determined from the measured particle heights.

The use of a NanoWorld AFM probe in tapping mode provided a suitable approach for imaging these nanoscale polymer-based structures while limiting the interaction between the AFM probe and the deposited nanoparticles. The NanoWorld PointProbe® NCSTR-50 AFM probe therefore played an important role in confirming the morphology and dimensions of the lignin-TPP nanofertilizers.

This work highlights how NanoWorld AFM probes can support nanoscale characterization of responsive polymer nanoparticles and advanced agricultural materials. By combining AFM-based morphological analysis with biochemical response testing and plant experiments, the authors demonstrate a promising approach toward nanofertilizers capable of delivering phosphorus in a plant-growth-synchronized manner.

The study also illustrates the broader potential of nanoscale characterization in the development of responsive agricultural materials, where nanoparticle size, morphology, stability, and stimulus-dependent behavior can all influence the performance of the final delivery system.

Figure 6.AFM images of cross-linked lignin/TPP nanoparticles after A) 0 h, B) 24 h, C) 48 h, and D) 72 h of incubation with acid phosphatase (10 mU/mL). — Figure 6.
AFM images of cross-linked lignin/TPP nanoparticles after A) 0 h, B) 24 h, C) 48 h, and D) 72 h of incubation with acid phosphatase (10 mU/mL).

Full citation:
Boarino, A.; Carrara, N.; Clua, J.; Zahnd, N.; Poirier, Y.; Klok, H.-A.
Plant-Growth Synchronized, Acid Phosphatase-Responsive Lignin-Based Controlled Release Phosphorus Nanofertilizers.
Biomacromolecules 2026, 27, 5, 3176–3187.
https://doi.org/10.1021/acs.biomac.5c02594

Creative Commons license: CC BY 4.0

NanoWorld – A New Look for Our Product Labels

Starting August 1, 2026, NanoWorld will begin introducing updated designs for many of our product labels.

During the transition period, you may receive products with either the current or the new label design shown below. The label version simply reflects the ongoing implementation of our new labeling system and is not related to the product itself or its date of manufacture.

The updated labels continue to display the nominal resonant frequency and nominal force constant of each AFM probe and now include a QR code linking directly to the corresponding product page. This provides convenient access to the complete set of available AFM probe specifications and related technical product information.

Products with multiple cantilevers (such as the Pyrex-Nitride Series) and customized products will continue to use their current labels, reflecting their specific labeling requirements.

While the labels are changing, the AFM probes themselves remain the same. We hope this update makes it even more convenient to access product information when you need it.

Current NanoWorld AFM probe product label showing the nominal resonant frequency and nominal force constant. — Current product label for NanoWorld AFM probes.

Updated product label on NanoWorld ESD-safe AFM probe packaging featuring a QR code linking to product specifications.

Nonlinear Optical Response in Layer-Stacked Gallenene with Ferroelectric Polarization

Layer-stacked gallenene is an emerging two-dimensional material with unique structural and electronic propertiesIn this article, M.Yunusa, A. K.Schulz, T.Parker, et al. investigated the nonlinear optical response of layer-stacked gallenene exhibiting ferroelectric polarization. The material was produced using a liquid metal-based synthesis approach and showed a phase transition associated with its stacked structure.

The authors demonstrated strong second harmonic generation (SHG) signals, revealing the nonlinear optical activity of gallenene and confirming its ferroelectric nature. These findings highlight the potential of gallenene as a novel functional 2D material for advanced optoelectronic and photonic applications.

Atomic force microscopy (AFM) was used to characterize transparent lamellar films and helical filaments. Measurements were performed using a commercially available AFM instrument operated in contact mode. A NanoWorld Arrow-CONTR AFM probe with a nominal force constant of 0.2 N/m and a resonance frequency of 14 kHz was used to obtain high-resolution surface morphology data.

*Figure 1*
Structure of gallenene and complex anatomy of supercooled liquid gallium. Mechanism for electrical and thermal perturbation. a) Illustration of hypothesized interaction of SHG response with SLG in linearly polarized light showing that thermal perturbations could align the 2D nanocrystals, allowing for an increased SHG medium at either temperature or electrical fields. An example HAADF image of gallenene flake sandwiched between two graphene layers, as depicted in (a) (far right microscope image). b) Structural reorganization of gallenene nanocrystals in the SLG leading to an intensity change in SHG signal as a result of thermal or electrical perturbation.

Full citation:

Yunusa, M.; Schulz, A. K.; Parker, T.; Schneider, F.; Elibol, K.; Predel, M.; Dzíbelová, J.; Rebmann, M.; Gorkan, T.; Ye, J.; Tan, J.-C.; Kang, W.; van Aken, P. A.; Meixner, A. J.; Durgun, E.; Kotakoski, J.; Zhang, D.; Sitti, M.
Nonlinear Optical Response in Layer-Stacked Gallenene with Ferroelectric Polarization.
Advanced Materials 2025, 37(44), e01058.
https://doi.org/10.1002/adma.202501058

Attribution 4.0 International By exercising the Licensed Rights (defined below), You accept and agree to be bound by the terms and conditions of this Creative Commons Attribution 4.0 International Public License (“Public License”). To the extent this Public License may be interpreted as a contract, You are granted the Licensed Rights in consideration of Your acceptance of these terms and conditions, and the Licensor grants You such rights in consideration of benefits the Licensor receives from making the Licensed Material available under these terms and conditions. https://creativecommons.org/licenses/by/4.0/