A gold–silver nanorod colour shift reports Salmonella after magnetic capture

A Scientific Reports study used selective magnetic capture and inhibited silver-shell growth to create a visible colour response.

Evidence summary

The reported workflow captured the target with aptamer-functionalized magnetic particles, then used bacterial sequestration of silver ions to change gold–silver nanorod shell growth and colour.

Selectivity comes before the colour

The visible colour is the final transduction step. Magnetic capture is used first to isolate the target from a complex sample, illustrating why a nanosensor is a workflow rather than a particle alone.

What this study does not establish

The magnetic enrichment and sample-preparation workflow is part of the result.
Detection limits, matrix effects and selectivity must be interpreted under the study conditions.
Field deployment and routine food testing require validation beyond one research study.