Hello there, curious researcher friend Gonzalo Adrián Ojeda! I understand your frustration and challenges with using the FRITSCH ANALYSETTE 22 NeXT Nano for characterizing green-synthesized silver nanoparticles. While I can't provide limitless solutions, I can certainly offer some guidance and insights to help you troubleshoot the issue.

Using this equipment for nanoparticle characterization can be tricky, but there are a few things to consider:

1. **Sample Preparation**: Ensure that your sample is well-prepared and properly dispersed. Aggregates or poorly dispersed particles can result in inaccurate measurements.

2. **Calibration**: Check if the equipment is calibrated correctly for your specific samples. This step is crucial to get accurate readings.

3. **Optical Properties**: The optical properties of your nanoparticles might differ from traditional standards, which can affect measurements. Make sure the equipment settings match the characteristics of your nanoparticles.

4. **Wavelength Range**: As you mentioned the maximums in the range of 420-470 nm, double-check that your equipment's wavelength range is set to capture this range.

5. **Sample Concentration**: Ensure that the sample concentration falls within the linear range of the instrument. If it's too concentrated or too dilute, it might not produce a reliable signal.

6. **Cleanliness**: Keep the equipment clean and free from contamination. Even tiny specks can affect readings.

7. **Particle Size Range**: Confirm that the equipment is suitable for the size range of your nanoparticles. Some instruments are optimized for specific size ranges.

8. **Consult Experts**: If you're still encountering issues, consider reaching out to FRITSCH's customer support or contacting experts in nanoparticle characterization. They might be able to provide specific guidance for your samples.

Regarding whether others have used this equipment for green-synthesized silver nanoparticles, I recommend checking scientific literature, conferences, or online forums. Researchers often share their experiences and methodologies. Additionally, reaching out to colleagues or mentors with expertise in nanomaterial characterization can be valuable.

Remember that troubleshooting is an integral part of research, and sometimes it takes time to fine-tune experimental parameters. Stay persistent, and I hope you Gonzalo Adrián Ojeda find the solution to your measurement challenges! If you have more specific questions or need further assistance, feel free to ask.