To address emerging climate and resource threats to global agriculture, we require advanced, plant-to-farm monitoring interventions. This perspective proposes Flora-Fi, an expanded Internet of plants framework leveraging innate intra- and interplant communication (IPC) pathways. By integrating biological signals with digital networks, Flora-Fi enables energy-efficient, early stress detection. We outline a blueprint detailing the next-generation sensing, communication, and data processing infrastructures necessary to realize this holistic crop management paradigm.

Nitrite (NO2-) is responsible for several physiological processes but can be harmful in excess. With rising exposure from food preservatives, fertilizers, and pollutants, accurate nitrite assessment is crucial for health and environmental safety. Different methods have been employed for its determination, with electrochemical sensors showcasing great promise. Single atom catalysts (SACs) are a class of nanomaterials that consists of isolated catalytic metal atoms anchored on conductive supports, which exhibit unique electronic properties with great promise for this application. The performance of these materials can be enhanced even more by incorporating a secondary metal in the catalyst structure. This leads to the creation of more surface-active sites and enables the facilitation of multi-step reactions. Herein, a bimetallic single atom catalyst (FeCoSAN) is synthesized through a single step laser assisted solid-process by anchoring iron and cobalt atoms while simultaneously creating a laser-scribed graphene (LSG) support. The presence of Fe and Co atoms is verified by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and X-ray absorption spectroscopy (XANES and EXAFS). Through electrochemical testing, the bimetallic system demonstrated excellent capabilities for determination of NO2, achieving up to 100% more efficiency, in comparison with bare LSG, with a detection limit of 2.42 mu m and a sensitivity value of 515.07 mu A mm-1 cm-2 over a linear range from 5.0 to 1666 mu m. This highlights their potential for in vivo and point-of-care sensing applications.

Conventional methods for monitoring water quality are often time-consuming, expensive, and lack sensitivity, making it difficult to detect contaminants before they enter the environment. Therefore, it is essential to develop sensing platforms that address these issues and that are capable of performing on-site detection. As such, in this study, we developed an electrochemical sensing platform for detecting pharmaceutical pollutants in water, particularly paracetamol (PCM) and acetylsalicylic acid (ASP). By minimizing the gap distance between the working and auxiliary electrodes of laser-scribed graphene interdigitated electrodes (LSG-IDEs), the sensitivity of the sensors was improved. The developed platform was compared to a standard LSGE design, and the LSG-IDEs achieved an 18.6-fold and 70-fold improvement in detection limits for PCM and ASP, respectively. The system was tested with real wastewater samples spiked with ASP and PCM, demonstrating its effectiveness in practical scenarios. Additionally, the system was successfully integrated with an on-site detection device, demonstrating its potential for real-time, portable water quality monitoring. The high sensitivity and low-cost of LSG-IDEs make them a suitable option for the monitoring of water quality and protecting public health.

The increasing prevalence of insulin resistance (IR) highlights the importance of early diagnosis and timely medical intervention. The ratio of adiponectin to leptin proteins (A/L) is believed to be a key indicator of IR, but the lack of adequate ways of tracking it prevents its clinical utilization. To that end, we have developed a laser-scribed graphene (LSG) based immunosensor capable of detecting adiponectin and leptin simultaneously. The sensors are decorated with gold nanostructure (AuNS) that are bio-functionalized with adiponectin and leptin antibodies via EDC/NHS covalent chemistry. We demonstrate that the immunosensor is suitable for clinical utilization, with a detection limit of 0.59 μg/mL for adiponectin and 0.18 ng/mL for leptin. Furthermore, the multiplexed nature of the assay allows for IR assessments at reduced sample volume whilst not compromising accuracy. Lastly, we validate the applicability of the immunosensor for point-of-care (PoC) settings by integrating with a customized miniaturized potentiostat connected to a smartphone application. The resulting device can be used for the facile quantification of A/L at clinically relevant accuracy, facilitating faster IR assessment relative to conventional methods that rely on independent measurements of the two biomarkers.

Precision farming is an optimized management farming scheme that seeks to link the real-time needs of crops with the nutrients to be administered. Sensing platforms that can monitor the physiological status of crops in situ are key to enabling timely and localized interventions. However, the underdevelopment of plant sensing strategies limits the potential of precision farming. In this Review, we discuss the challenges and advancements in phyto-monitoring, focusing on strategies that are applicable to a wide range of plant species and suitable for field deployment. We explore species-agnostic sensors, including optical and electrochemical sensors, whose operation is based on principles that are widely applicable to all plant species. These platforms enable real-time monitoring of the physiological state of crops by assessing key biomarkers, such as plant hormones, and metabolites such as salicylic acid and reactive oxygen species. Evaluating these systems, we conclude that an integrative sensing approach is necessary to compensate for the limitations of the individual methods and can provide a holistic view of crop health. Cost-effective species-agnostic sensors are thus needed to provide information that can be used to minimize the resource footprint of farming and meet the growing global demand. Species-agnostic plant sensors can monitor the physiological health of a broad range of crops, which is vital for the implementation of precision farming. Here, we evaluate the different sensors in terms of their effectiveness and propose an integrated sensing approach.

A multimodal sensing approach enables the holistic collection of data, enabling a more comprehensive analysis and predictive capabilities for disease screening. Despite the advantages of fusing multiple sensing modalities, the approach is challenging due to the need for multiple sample types, which can lead to extensive sample preprocessing and potential cross‐interference. In this study, we developed a portable multimodal sensing system for diabetes screening that integrates an electrochemical sensor and a chemiresistive gas sensor for the simultaneous detection of glucose and acetone vapor from the same urine sample. We demonstrate that the use of commercial glucometer strips in urine does not compromise the performance of an accompanying metal oxide‐based gas sensor, and vice versa. The device provides readings comparable to benchtop equipment ( R 2 = .9662) for the electrochemical sensing and gas sensing ( R 2 = .9645). The combined information may help screen for diabetic patients without the need for invasive sample acquisition, which highlights the importance of advancing integrated systems to address complex screening challenges for multi‐parametric diseases. This can contribute to improved health outcomes for individuals at risk of diabetes and other metabolic disorders.

In this work, we present a non-enzymatic glucose sensor based on cobalt oxide-modified laser-scribed graphene (LSG) integrated into a microfluidic platform. Cobalt oxide was electrodeposited directly onto porous LSG and thermally annealed to form a CoO/Co3O4 phase with enhanced redox activity. To enable detection in near-neutral urine samples, an alkaline buffer hydrogel was incorporated into the chip for in situ pH modulation. The device was validated using artificial and human urine samples, demonstrating reliable glucose detection without enzymatic reagents or external preprocessing. This system offers a flexible and scalable approach for point-of-care metabolic screening.

Laser-scribed graphene electrodes (LSGEs) are promising platforms for the development of electrochemical biosensors for point-of-care settings and continuous monitoring and wearable applications. However, the frequent occurrence of biofouling drastically reduces the sensitivity and selectivity of these devices, hampering their sensing performance. Herein, we describe a versatile, low-impedance, and robust antibiofouling interface based on sulfobetaine-zwitterionic moieties. The interface induces the formation of a hydration layer and exerts electrostatic repulsion, protecting the electrode surface from the nonspecific adsorption of various biofouling agents. We demonstrate through electrochemical and microscopy techniques that the modified electrode exhibits outstanding antifouling properties, preserving more than 90% of the original signal after 24 h of exposure to bovine serum albumin protein, HeLa cells, and Escherichia coli bacteria. The promising performance of this antifouling strategy suggests that it is a viable option for prolonging the lifetime of LSGEs-based sensors when operating on complex biological systems.

Real-time monitoring of phytohormones in horticultural plants is difficult due to the lack of biosensors for these systems. Phytohormones that are associated with biotic stress responses, such as salicylic acid (SA), indole-3-acetic acid (IAA), abscisic acid (ABA), and auxin, can be detected using chromatography and fluorescent sensors, but these techniques are not suitable for field deployment. The electrochemically active nature of phytohormones can be exploited to detect these molecules in living plant tissue. Incorporating phytohormone-selective minimally invasive electrodes allows for continuous monitoring applications. This strategy can also be applied to electrochemically inactive phytohormones by utilizing impedimetric measurements.

The rising global occurrence of plant pathogens highlights the need for a thorough reassessment of current disease detection and management schemes. To that end, we review the utility and limitations of the available sensing platforms deployed for phytodiagnostics in the field. We also discuss recent advances in the use of broad-spectrum biomarkers such as phytohormones and volatile organic compounds (VOCs), and assess the feasibility of deploying these platforms on a large scale. Because these platforms are often complementary, we propose a compressed sensing approach that combines several sensing platforms to manage plant pathogens while minimizing additional costs. Finally, we provide an outlook for the potential benefits of integrating new sensing technologies into farming for timely interventions.

We present an electric power meter that capitalizes on the interaction of electrothermal strain and mechanical vibration in a micro-electro-mechanical systems (MEMS) beam undergoing the antisymmetric mode of vibration. This is achieved by using a resonant bridge driven with an electrothermal modulation technique. The change in electrical power is monitored through the alteration in the mechanical stiffness of the structure, which is tracked electrostatically. The observed deflection profile of the beam under the influence of electrothermal effects shows that the deflection geometry due to buckling exhibits similar trends as the first symmetric vibrational mode, in contrast to the antisymmetric mode. Therefore, we compare two distinct vibrational modes, converting the compressive thermal stress generated by the input electrical power via Joule heating into a shift in the resonance frequency. By employing antisymmetric vibrational mode, the output of our device is consistently monotonic to the input electrical power, even when the microbeam is experiencing buckling deflections. In addition, the sensing operation based on antisymmetric modes yields only a 1.5% nonlinear error in the response curve, which is ten times lower than that of symmetric modes. The observed deformation shape of the resonator agrees with the results obtained from multi-physics finite simulations. Finally, this approach has the potential to be extended to other frequency-shift-based sensors, allowing for higher linearity.

In this paper, we present a minimally invasive sensor for the assessment of plant health, based on functionalized inter-digitated electrodes decorated with microneedles. The shaft length of the needles is tuned to pierce the cuticle of the leaf to gain access to the mesophyll layer, where the monitoring of bioimpedance and electrochemical detection of salicylic acid, a phytohormone, is possible. A functional coat of molecularly imprinted polymers is utilized to pre-concentrate the phytohormone around the electrodes to achieve a sufficiently low limit of detection of 2.74 μM. We demonstrate the performance of the device for the in situ detection of salicylic acid and monitoring the diurnal cycling of bioimpedance of live plants to identify light stress.

To keep up with population growth, precision farming technologies must be implemented to sustainably increase agricultural output. The impact of such technologies can be expanded by monitoring phytohormones, such as salicylic acid. In this study, we present a plant-wearable electrochemical sensor for in situ detection of salicylic acid. The sensor utilizes microneedle-based electrodes that are functionalized with a layer of salicylic acid selective magnetic molecularly imprinted polymers. The sensor's capability to detect the phytohormone is demonstrated both in vitro and in vivo with a limit of detection of 2.74 μM and a range of detection that can reach as high as 150 μM. Furthermore, the selectivity of the sensor is verified by testing the sensor on commonly occurring phytohormones. Finally, we demonstrate the capability of the sensor to detect the onset of fungal infestation in Tobacco 5 min post-inoculation. This work shows that the sensor could serve as a promising platform for continuous and non-destructive monitoring in the field and as a fundamental research tool when coupled with a portable potentiostat.

Precision farming has the potential to increase global food production capacity whilst minimizing traditional inputs. However, the adoption and impact of precision farming are contingent on the availability of sensors that can discern the state of crops, while not interfering with their growth. Electrical impedance spectroscopy offers an avenue for nondestructive monitoring of crops. To that end, it is reported on the deployment of impedimetric sensors utilizing microneedles (MNs) that can be used to pierce the waxy exterior of plants to obtain sensitive impedance spectra in open-air settings with an average relative noise value of 3.83%. The sensors are fabricated using a novel micromolding and release method that is compatible with UV photocurable and thermosetting polymers. Assessments of the quality of the MNs under scanning electron microscopy show that the replication process is high in fidelity to the original design of the master mold and that it can be used for upward of 20 replication cycles. The sensor's performance is validated against conventional planar sensors for obtaining the impedance values of Arabidopsis thaliana. As a change is detected in impedance due to lighting and hydration, this raises the possibility for their widespread use in precision farming.

Microneedles (MNs) are playing an increasingly important role in biomedical applications, where minimally invasive methods are being developed that require imperceptible tissue penetration and drug delivery. To improve the integration of MNs in microelectromechanical devices, a high‐resolution 3D printing technique is implemented. A reservoir with an array of hollow MNs is produced. The flow rate through the MNs is simulated and measured experimentally. The mechanical properties of the 3D printed material, such as elasticity modulus and yield strength, are investigated as functions of printing parameters, reaching maximum values of 1750.7 and 101.8 MPa, respectively. Analytical estimation of the MN buckling, fracture, and skin penetration forces is presented. Penetration tests of MNs into a skin‐like material are conducted, where the piercing force ranges from 0.095 to 0.115 N, confirming sufficient stability of MNs. Furthermore, 200 and 400 μm‐long MN arrays are used to successfully pierce and deliver into mouse skin with an average penetration depth of 100 and 180 μm, respectively. A biocompatibility assessment is performed, showing a high viability of HCT 116 cells cultured on top of the MN's material, making the developed MNs a very attractive solution for many biomedical applications.

This paper presents an impedimetric biosensor for monitoring of crops using novel microneedle electrodes for minimally invasive, sensitive measurements, compatible with smart agriculture developments. The biosensor was fabricated through polydimethylsiloxane imprinting using a high-resolution 3D printed negative mold. This method allows for fabrication of tailored microneedles with heights up to 500 μm, required to penetrate through the epidermis of a leaf. The sensor was tested by recording the bioimpedance of Barely leaves and comparing its performance to conventional planar and needle electrodes. Furthermore, we present evidence of a diurnal pattern in plant bioimpedance that was detected by monitoring the leaf bioimpedance under controlled conditions.

A miniaturized drug delivery system suitable for in-vivo biomedical applications is presented. The system consists of an electrolytic pump driving a micro bellows membrane as an actuator for delivery through microneedles. A two-photon polymerization 3D printing technique was used to fabricate a reservoir equipped with microneedles. Analytical characterization of the flow rate through the microneedles showed an outgoing flow rate ranging from 63 μL/min to 520 μL/min for an applied pressure of 0.1 to 1 kPa. The assembled system with an overall size of 3.9 mm × 2.1 mm × 2 mm achieved delivery of 4 ± 0.5 μL within 12 seconds of actuation. A penetration test of the microneedle into a skin-like material confirms its potential for transdermal delivery.